defective bags???

my friend has a s-10 that has slam rs-6 bags up front and has a factory 4.3 motor...i dont know how heavy that motor is but it takes about 120lbs to lift the front completly up...which really isnt too bad, but the other day his right front bag blew a hole in it, the bag didnt rub nothing, it blew a hole in it and the otter rubber is split or cracked like the bag had a zit or something n blew a hole, i can peal back some of the rubber and i can see the inner bead...it leaks pretty bad...any idea what the hell happened to this...the only thing i could think about is that there was too much pressure(180psi at the most) or the bag was defective n just took a shit...but i know for a fact it wasnt rubbing