Unfortunately IOS crashes due to software bugs are not rare. Not necessarily these are handled by PSIRT, else they would have their hands quite full, let me tell you.
Your only option is to upgrade to latest release (11T or 11XJ as of now) and if it happens again, open a case with the TAC.
Be prepared to supply all the required traces, work with the engineer to have him/her reproduce the problem in lab, and file a bug. It can be a lengthy and painful process.