So the issue I was working on for last 3 days turned out to be an OS specific issue in a partner team.
Lesson repeat: Sometimes it is a good idea to timeout on your investigations if you’re not making expected progress and ask for help. Applies more if you’re new to the system. Though it’s always good to read through the source once :) Doesn’t apply if a) you are bored or b) you are curious (adamant?) enough to learn how the stupid system works. Final lesson, when stuck on debuggers, use windbg/sos/sosex. Trust me on that. *Well, I started with (a) above and in the process moved to (b). Just for the fun of it ;)*