>>apetre+qd
In the post, he says the deal was going to be getting hired and getting a bonus as compensation in exchange for him bringing AppGet's code into Microsoft and leading the project. That's a very simple deal in which no ownership of other projects is being transferred.
I'm not a lawyer but I'm pretty sure that hiring someone doesn't mean that you grandfather their liabilities. If that were the case the world would be chaos.
If Sonarr was the reason to reject him then it was done out of complete pettiness.