In his next press conference, Van Gaal unleashed a staunch defence of United's tactics.
In front of stunned journalists, he handed out leaflets containing statistical analysis that, according to him, showed that Allardyce was wrong.
The horrified look on a press officer's face when he produced his sheets of paper said it all.
'I have made an interpretation of the data for this game and then I have to say that it is not a good interpretation from Big Sam,' he quipped.
Speech at 2014-15 end-of-season awards
The Dutchman has never been shy of expressing himself and his end-of-season speech last year, certainly testified that.
Van Gaal, who had earlier in the evening clipped assistant manager Ryan Giggs around the ear for attempting to outbid him in an auction for a round of golf with ex-Reds star Dwight Yorke, took the stage at the end of the night to deliver a memorable speech.
Akin to Winston Churchill at times, Van Gaal's speech soon became a viral hit.
Bust-up with Victor Valdes
Van Gaal's signing of Victor Valdes seemed shrewd business in his first season. The former Barcelona goalkeeper was a trusted ally after building a rapport with him for 13 years.
However, that sentiment went out of the window when he confirmed that the exit door was looming for the Spain international after he apparently refused to play for the reserves.
'Last season, he refused to play in the second team and there are other aspects you need as a keeper at United,' Van Gaal said during the pre-season tour of America last summer.
'When you are not willing to follow those principles, there is only one way and that is out.'
Calling Chris Smalling, 'Mike'
Having been at Old Trafford for a season, you would've assumed that Van Gaal knew his players pretty well - including their names. You would be wrong.
During last summer's pre-season tour of America, the Dutchman appeared to get his wires crossed when he referred to Chris Smalling as 'Mike'.
Van Gaal made the gaffe whilst on the subject of various captain's roles he has allocated at the club, but was quick to realise his error when a journalist addressed the defender immediately after.
'I think he is a great captain, better than I had expected and he is fully expected by the players and that is also very important because I can choose but the players decide,' Van Gaal said.
'That's my philosophy, the players have to accept the captain - the first captain is Wayne Rooney, the second captain is Michael Carrick and last year the third captain was Mr Mike Smalling, sorry, I mean Chris Smalling.'
Louis van Gaal's army!
Groans of discontent among the Old Trafford faithful had begun to grow as United dropped five points from their opening four Premier League games this season.
Ahead of their next match against bitter rivals Liverpool, Van Gaal insisted the Red Devils were fully behind him - imitating them with a rendition of their song about him.
'The fans are shouting every week, "Louis van Gaal's army! Louis van Gaal's army!", so also the fans are very satisfied with Louis van Gaal and my players are also satisfied with me,' he said.
He even slapped his hands to replicate the noise made by United supporters as they chanted his name. Eccentric indeed.
Enjoy the wine and a mince pie!
By December, questions surrounding Van Gaal's future at Old Trafford had intensified following a winless run of six matches.
Angered by speculation that he could be replaced by Jose Mourinho, he came out fighting in a 4min 58sec press conference ahead of their Boxing Day clash at Stoke City.
'I think I was already sacked, I read,' said a fuming Van Gaal. 'My colleague (Mourinho) was here already.
'What do you think happens with my wife or with my kids or with my grandchildren or with the fans of Manchester United or my friends? They have called me a lot of times.
'Has anybody in this room not a feeling to apologise to me? That's what I'm wondering.
'So you think that I want to talk with the media now? I am here only because of the Premier League rules.'
As he concluded his rant, Van Gaal finished with: 'Enjoy the wine and a mince pie. Goodbye.'
Van Gaal vs 'fat man' journalist
Just weeks after his festive rant at the press, Van Gaal chose not to mince his words once again.
The Dutchman refused to talk about his captain Wayne Rooney who had scored twice in their 3-3 draw at Newcastle.
However, before leaving the room a visibly irate Van Gaal turned around, pointed at Sun reporter Neil Custis and delivered his insult.
When it was put to Van Gaal, 'Wayne Rooney has taken a lot of criticism this season...' he interrupted the question and stood up before saying: 'We don't speak any more about Wayne Rooney, yeah? You have criticised him, I don't. You.'
Van Gaal then overheard an exchange between reporters and returned to the press room, adding, 'You too, fat man, there,' pointing at the journalist and suggesting he was among those who had been critical of Rooney.
Wanting 'horny' players
'We have to keep the ball better and we have to move the ball quicker - that's always what we have to do. Desire... it is a great word. I often use the word "horny" with my players.'
Looking for inspiration against Midtjylland in the Europa League round of 32 second leg, Van Gaal sought an unusual reaction from his team to overturn a 2-1 deficit.
It worked though as United ploughed the Danish side's defence throughout the match to win the second leg 5-1 and progress 6-3 on aggregate.
Falling over against Arsenal
Van Gaal has been criticised for showing a lack of passion on the touchline by the Red Devils faithful but the Dutchman showed plenty during their 3-2 Premier League win over Arsenal in February.
In a peculiar but funny moment, Van Gaal was seen hurling himself to the ground after a discussion with fourth official, Mike Dean.
Unhappy at the perceived theatrics of Arsenal's Alexis Sanchez, the United boss made his feelings clear to Dean by mocking his actions on the touchline.
His colourful protest drew an enormous cheer from United fans, and even a sporadic and rare outburst of 'Louis van Gaal's red-and-white army' from the Stretford End.
'Sex masochism'
Following this month's 1-1 draw at home to eventual Premier League champions Leicester City, Van Gaal pulled a Sky Sports reporter's hair in a bizarre post-match interview.
Van Gaal's action was in relation to his perceived view of Robert Huth's act on Marouane Fellaini which saw both players slapped with three-match bans by the FA for violent conduct.
The United manager wanted to get his point across after being asked by Patrick Davison about an incident between his midfielder and the Leicester City defender - describing it as only acceptable in 'sex masochism'.
'When you see what Huth is doing to Fellaini, that's a penalty,' Van Gaal told Sky Sports.
'Shall I grab you by your hair? What is your reaction when I grab your hair?
'Your hair is shorter than Fellaini but when I do that, what are you doing then? It's a reaction.
'Every human being who is grabbed by the hair, only with sex masochism, then it is allowed but not in other situations. They did it. They did it several times I think.
'Huth was the guy who grabbed the hair of Fellaini. I think the reaction of Fellaini is like a human being. He is always like that.'
