im lost.. what happened?

ok so my buddy has a b16a swap in his 88 crx dx. well he went outside the other night and started it to warm it up and went back inside before he left. well he came back out(car still runnin) got in, shifted to reverse and dropped the e brake and for some reason the car started to spit and sputter then died. never took his foot off the clutch. started it back up and immediatly spit and sputtered. ran for a min like that and it died and wont start. has fuel spark and air. timing is still correct. wtf happened?! i appreciate any help.