I got the same impression DC, and think it may come back to Tony. Bobby was sloppy I think, leaving the ripped part of his shirt, and although I see others' point, I don't know that I'd have dropped the gun right there in the laundramat.
What "could" happen is, Bobby will be tracked down by the police and as someone else here said, will turn states evidence agains Tony to save his own skin. Yea, they are all murderers, but I see Bobby thinking about his family and doing whatever it takes to get out of jail. Then again if that happens and he rats on Tony, he could die before he even gets a chance to testify. .
Bada Bing!!! There's another last season whacking.
TIS