I've had a 5DII for a year or so. It's gotten slightly wet in thunderstorms several times and, a few months ago my tripod and 5DII blew over in a sudden wind gust in the Bisti Badlands. Tripod was extended about 5 ft, I turned my back to get a polarizer, turned around and the camera (at first thought) was gone ! (lots of theives in those badlands
. Anyway, neither falling into the hard clay/sand or getting wet has caused any problems so I'm a happy camper.
OTOH, the lock knobs on both my TS-E II 24 mm and TS-E 45 mm have gotten stuck for no apparent reason. Canon repaired them both for free under warranty (very fast return) and now that the lenses have been used more the tendency for those knobs to stick has disappeared.