You better believe it is a captured Grizzly. Here are a couple of other photos I have of the Serb Grizzlies, they even have the add-on ceramic armour and Kevlar covers:
I am not exactly sure about the details of the capture. Grizzlies didn't arrive in Bosnia until late September 1994 just as I was leaving, I was in charge of the guys that picked them up from Split in Croatia, so they must have been captured in late 1994 or in 1995 prior to IFOR arriving.
I think that the image you posted is the same vehicle in the second image I posted...so there must have been at least two captured.
I believe they were acquired by the Serb "Special Forces"/"Internal Security Forces".