No my point was that if a critical bug appears in the system and you, the original contractor, has dropped off the radar (or whatever) they stand a much higher

No my point was that if a critical bug appears in the system and you, the original contractor, has dropped off the radar (or whatever) they stand a much higher chance of finding someone to fix it. This is what we do for Bank software; they find a critical flaw that needs fixing and it is our job to hunter-killer for it and work with their team to nail it and integrate the solution. I agree with the point you were making; just I felt the example was more driven by a different need (one very specific to that piece of software) (or look at it another way there is much more likely to be a C programmer with experience in ATC software, an important sub-skill in this case, than a Scala one :D)