I wouldn't bet on that. With the exception of some of the US-built cheapies [those 55-round monstrosities in particular] AK magazines are about as reliable as it gets. They're developed, after all from that of the WWII Bren gun [look at the front pivots of an AK and BREN magazine, or the mag of the 7,92x57mm Czech ZB-26 from which the Bren was developed.
If I had to bet without seeing, I'd bet on a combination of lousy corrosive ammo and failure to clean the gas systems after previous shooting. I've seen that in AKs used by those who care for them haphazardly, as well as in many of the SKS-45 carbines owned by civilian shooters in the US. They're not particularly difficult weapons to maintain, but they do require at least a minimal amount of operator attention now and again.
-archy-/-