It's VERY possible a puffed pack could come to the surface! I'm not saying that it's a guarantee, but I do have a hypothesis as to why this may take place if it indeed does. The gas that is produced in a puffed Lithium polymer pack is Hydrogen. A hydrogen filled polymer balloon could very well make it to the surface if there were sufficient hydrogen to overcome the weight of the 'wafer' in there.
As far as "who comes up with this stuff", I believe the guy that had the incident did!
Maybe he just made all that up...yeah, that's it...rrrrrright.
Ever heard of a thing called BUOYANCY kit?!?