Yildiz said Dawson was in Spy Bar by himself early on Friday morning having a drink and chatting with staff.
"He was just to me a normal, good-mannered guy, nothing wrong."
Yildiz said the Spy Bar doorman witnessed the incident when Dawson left the bar about 1.30am.
The doorman told Yildiz that Dawson started to argue with a couple of men, then one of the men punched him.
Yildiz said the men Dawson encountered were not in Spy Bar that evening.
He said Spy Bar staff called the ambulance and police.
Herald on Sunday social columnist Rachel Glucina said Spy Bar had been a haunt of celebrity Kiwis for years including model Nicky Watson.
Sky News spokeswoman Kirsty Way said Dawson had been working in the Rugby World Cup production team as a specialist EVS operator providing slow motion replays.
He started out working for Sky News in Christchurch in 2004 then came to work for the Auckland branch in 2005.
"He was well known and respected and had many friends at Sky, he will be sorely missed. Our thoughts are with his family at this time and we have taken steps to care for our staff as they come to terms with the loss of Billy."