He is on a mtb, so naturally is 2 holes spd cleat. dont think u can use 3 holes cleat with mtb shoes... maybe not shimano anyway, speed play, yes.
why clip in one leg and not the other? defeats the purpose of using clipless honestly. the more you do that, the less you will get used to unclipping. Train your muscle memory to unclip then it becomes 2nd nature. I frequent ECP from my place via PCN, never encountered any incident with exception to ECP, alot of close shave, jam braking. But never fail to unclip. I use clipless on both my tyrell and brompton, but mainly because I hate the sensation of getting my shin whack an scratch by the pedal.