rear gear oil pushed out

on my way to the trail i soaked the guy behind me in gear oil when it pushed out....it appeared to have pushed out of the left side of the houseing where the axle tube is pushed in.....but after checking for a crack i couldnt find one...so i filled it back up and wheeled all day and drove it home without any leaking....which kinda makes me mad because now i have no idea what i should do about it....my guess is that it might have pushed out the vent maybe it was over filled or the vent was blocked and when pressure built up it popped the block and shot out oil that leaked down all over the rear...so anyway any body have any problems like this or know of any? anyone have to replace the pinion seal because of a one time oil leak...

i have a 91 xj with the 35 and 308's ezlocker thanks guys