I recently saw Antonius in a showdown playing PLO where he was big favourite to win. The other guy was a 27% dog! They decide to run the turn and river 4 times and the underdog took down all 4!!!! OMG.
I'm pretty sure Robl used up almost all of his outs in order to win all 4 all-ins. Pretty sick.
It's pretty hard to calculate exactly how likely it is with all the redraws in PLO though, as opposed to some situation where someone was all-in and had 6 pure outs and had to run it four times.