My '04 Pontiac Montana just spent three days in the shop getting a loose rocker arm fixed that also caused a bent push rod. The tech tells me this is very rare, in fact he's never seen it and has no idea how it happened.
It should be noted that at about 10K the head gasket blew and this same shop did the work. Do the techs need to mess with the rocker arm when repairing a head gasket? If so, I believe I have found my culprit.