Another bad rap for solo diving! IMHO, The first thing that went wrong, was situational awareness. HOW,, did you become entangled? You were'nt paying attention, slacked a line, instant trouble. You should'nt even have considered a solo without the proper rig, training, and most imporantly EXPERIENCE. And not to be a hard *****, you need to stick to pool depth, and drill your but off until you can sweep that reg back in your sleep, or remember you have an occto, that I assume you check, and USE on a regular basis. A pony, redundant system is only good if you remember its there, AND, you have practice in getting it deployed. Im also a little concerned over your question on DCS, 15 feet?? The only real danger(s) were drowning (panic) or embolism (panic) Both of which are relitavely undesireable. I see by your bio, that you seem to have enough dives under your belt that this shuld never have happened to you. Nothing will hunt you down and kill you faster than panic, while you will never eliminate it, you can keep it at bay by having automatic responces to situations that may arise. Work on them.