Ha! I guess it depends. If you make the beach alive, then punishment enough for blowing your dive plan is having to hump all the way back to your car which has since been ticketed by HPD, towed away, its locks punched and wheels listed on e-auction. OTOH, if you had the bad taste to drown and the tides have switched the Molokai Express in the right direction, you might get snagged in the spin cycle at Witch's Brew and draw frowns from: 1) the tourists for the stinking up the view; 2) the Bay admins for abnormally feeding the fishes; 3) the lifeguards/HFD/EMS/coroner's office for having to heave ashore and pack up your gray bloated water-logged carcass then scratch back up the Bay's hill with it; and 4) HPD for having to fill out all the paperwork. Oh, and let's not forget; 5) your survivors/estate for the ticket and towing charges.
Seriously, I haven't been off of either Portlock or Lanai Lookout at night but just from a couple of daytime experiences, unless you're really familiar with the dive and even then, I strongly recommend having somebody(s) as shore watch. Portlock/China Walls shouldn't be too bad in general but I'd forget about trying to make an exit at the original Koko Kai entry; might be better to come out further down to Koke'e Park, in the lee of a thing we called Finger Rock. But the LL exit can be tricky enough to find during the day with the whitewash and surge; it's just a chute or trough draining the rock shelf it's carved in. At night with no streetlights and virtually no visible fixed landmarks or depth perception, it's not something I'd care to try myself. IIRC, apparently a previous poster on this forum (ch0ppersrule ?) did LL going the other way (daytime) to land at Sandy's, which is something I never thought of trying. Besides the distance, switching currents, and coming through Sandy's shorebreak, I'm leery of crossing fishermen along the way. Bumbling into their typically heavy gear wouldn't be fun; not to mention pissing them off royally and possibly getting stoned. Also, lost fishing gear in that area can be a hazard; big tangles of heavy monofilament, wire leaders, weights, and wicked big hooks that'll do a job on your BC if not your tender hide. If you dive Halona Cove, you'll almost certainly come across some of that stuff; Bamboo Ridge is right around the corner. Packing EMT shears or other heavy snips is a must.
This is years old info; probably way different now. But we used to regularly snag lobsters at night up at Kaneana, directly across the street from Makua Cave in remotest Waianae. The diving spot most everyone does is landmarked by an awash finger shelf extending seaward. We dove a couple hundred yards left of that. IIRC, shallow, about 20-25ft. Sandy bottom with isolated outcrops of rock and coral. Good spot to see juvie pennant fishes. (In fact, I suspect this where John Hoover got his published pics of juvie pennants and tagged the location as Makua.) There were always rumors of a big tiger that cruised the area; i.e. lobsters = food. But we always figured on being more heads-up and swimming faster than our buddy -- "Gee dude, 'sucks to be you", that kind of thing.