OP, 6 months ago I hit a pot hole on a road trip. Two tires, 3 wheels, all wheel bearings and struts, both headlights and re-sheet metal the whole engine bay (damage to struts bent the metal firewall to bumper on both sides). I had no engine damage with this $18,000 claim. Just throwing this out there I think engine failure will be a stretch considering I hit the worst of potholes lol. Granted it conditions vary and something could most definitely gone wrong to cause mass oil leaks but judging from my pothole incident I'd say the motor fairs well on extreme impacts.
Like I said before best of luck buddy.
Edit: sorry for poor grammar iPhone changed some words and too lazy to fix.
BSM 2008 135i
-VRSF 7" IC -VRSF DP's -n55 mids -BERK race -ER CP -TIAL BOV -BMS DCI -JB4 G5 ISO -ST coils -STOPTECH slotted rotors & pads -SLeK lip