"It was basically a straight forward car accident where there was one party more at fault.
"We've got that time of year where there's parties going on in the weekend and somebody knows somebody else who sends out a text and the next thing you know some locals are down there, fuelled up, ready to cause trouble.
"Whether they were doing it out of a sense of justice or whatever I don't know but they were obviously coming to cause trouble and to pick a fight and of course well, we have to stop them."
A couple of his crew were on the receiving end of a few jabs as they tried to keep the drunken intruders from entering the crash scene.
The incident had riled up locals who were expressing their anger and disappointment on social media, with one saying "assaulting fire fighters about as low as you can go. Absolutely disgusting. Hope they see these comments and go and apologise", while another said it happened outside her house.
"All young locals in both cars. There were a number of fights between them which we were constantly breaking up, too much alcohol and testosterone! The firefighters were there en masse, did a fantastic job, cops took hours to get there, they were snowed under with crate-day incidents."
Harwood said a couple of his crew suffered bloody noses from being on the receiving end of a couple of jabs from the drunken louts, but added "it wasn't that bad".
"It was just a matter of defusing the situation."
Harwood said it wasn't firefighters' jobs to protect a crash scene from drunken young people trying to attack emergency services staff - and said the bigger issue was the lack of policing in the area.
"I think there's a message here that I would like to say, and what's really disappointing is that they took our local police away from us. Now, Waihi Beach and Athenree is a dynamic, growing area and I don't know where the decision came from, further up the chain, I imagine.
"They took our local police away from us and they sent them to Paeroa and that was a really sad day and a really short-sighted day and I think the police nationally need to look at putting constables back into our small town."
Waikato police began a review of the number of stations and officers in its district in 2015, resulting in a number of station closures and officers transferred to other areas.
Compounding police response time was the fact a slip had blocked both lanes of the Waikino Gorge, State Highway 2, meaning the closest officer had to travel from Whangamata, about 20 minutes away.
However, once trouble started unfolding and St John Ambulance staff put out an alert there was trouble "all of a sudden when that went out there were police for Africa".
"But what I'm saying is, there was a hang of a wait and if they had been present from the get-go sometimes just the presence of police can make people back off and I think that's the message that I would like to get out.
"There's local police living there, they should have a system where they can pull them into service immediately if it's possible, but why take our little police stations and shut them down in the first place? That probably annoys me more than anything."
He said an incident like the one last night was unusual, but not surprising as it was coming into the busy season, however he would now just hope it doesn't happen again.
"This doesn't happen very often and may not happen for a long time, so fingers crossed, eh."
Fire Service Communications shift manager Craig Dally earlier told the Herald there was a crowd at the scene and some of them had been drinking.
"There were some intoxicated people there that assaulted a couple of firefighters - there was a bit of a punch-up."
Dally said the firefighters' injuries were "very minor" and included a bloody nose.
Two people involved in the crash were taken to hospital for treatment to some minor injuries.
