Man works in Team A working on Product X

Man find problem in Product X , reports it, it is not fixed ..

Man leaves to join Company B working on amongst other things Product X (which is why they hired him), points out that the bug still exists and could cause problems

Man announces to the world he will demo the bug to the world (thus allowing Team A to actually have time to fix it...)

Sounds like closed source development to me ....when you don't tell anyone there is a problem don't let anyone leave unless they tell someone....