Look at this release schedule of games GRIN made, all for at least 360, PS3, and PC:
Wanted: March 17, 2009
Terminator: Salvation: May 19, 2009
Bionic Commando (next-gen version): May 19, 2009 (PC version July 17, 2009)
Along with this they were working on Fortress, and seeing some of the material that leaked out, they had obviously put some significant work into it already.
That's four major games, for a studio that was way too small for it. It's their fault for taking on so much work at once...it also doesn't help that the 3 aforementioned games kinda bombed. So all of this has contributed to their demise, not one bad deal.
Having a publisher with deep management issues and combining it with a small studio not known for great quality that happens to be working on too much at once is a recipe for disaster.