But in a lesson to us all, the former South Auckland lad has moved on and just wants to go racing.
"People who carry grudges are akin to having a ball and chain around their ankle holding them back from getting on with their lives.
"When I left [McLaren F1] I wanted to do something in racing and sports car racing had been in the doldrums for a number of years, but now it's picking up. I'm coming into the series with a new car and a new team.
"I get on with all the McLaren people and what happened, happened. It's history now," said Ryan.
With that attitude it comes as no surprise that Ryan and his team had a successful first outing as a customer team for McLaren GT, part of the McLaren Group, who make the cars.
There were three MP4-12C GT3 cars entered in the Spa-Francorchamps race and Ryan's team was the most successful, finishing mid-pack in a field of 62 cars.
As part of the driver line-up was a Kiwi, Roger Wills, who shared duties with Phil Quaife, Adam Christodoulou and Glynn Geddie. One of the other McLaren cars had an incident and ended up in the wall while the third entry caught fire.
"You only do your first race once and to bring it home in a 24 hours race isn't too bad, I guess.
"The car went really well and we're really pleased with it. It's a bit brave racing a car this early in its development phase and because of that you don't really know what you're going to come up against. We're quietly confident," said Ryan.
Although Ryan had the ultimate say in pretty much everything racing when he was the sporting director at McLaren F1, being in charge of your team comes with added pressure.
"In the past I put all my effort in for other people but now it's all mine. I spent most of my time at Spa watching people walk past the car hoping they wouldn't scratch the panel, as I would have to pay for it.
"I looked around and saw how much equipment I've already got but realised I need a lot more and that's a pretty bloody scary thought.
"I can't just knock on someone's door and tell them I need this and I need that. I have to find it myself," said Ryan.
The former McLaren F1 man, and now current race team owner, is pleased to be back in pit lane doing what he does best. With McLaren entering GT3 racing and rumours of a number of other new teams throwing their respective hats into the ring, look for the category to grow and get stronger.