I used to ride alone all the time and I survived, but I can't look bad and say I made all the appropriate decisions. My take on it is that I still wouldn't recommend it, but I won't tell someone I know to be disciplined and experienced not to. I'd suggest the following rules:
1) Only ride where there are other people around and don't ever be the last one out.
2) Always have a plan and tell a responsible party what it is, as well as giving an "if you don't hear from me" time.
3) Always carry an emergency signaling device (SPOT, inReach, RescueMe, etc.).
4) Always carry provisions for food and shelter to last you a couple nights.
5) Don't ride in known avalanche zones or questionable terrain unless others can see you.
6) Don't ride in bad conditions, and turn around if the weather goes bad.
I'm sure some could add to this, while others would say "never ride alone." With good reasons. The truth is, it's all a risk decision. The reality is there are probably more killed in avalanches than cases like this. The way I see it, someone riding alone but being disciplined isn't necessarily taking any more risk than someone riding slopes with avalanche potential, no matter how well trained and equipped, and what group they're in. Obviously I don't see it as a non-starter, but it does limit you a lot unless you accept some pretty dangerous situations (which you shouldn't). Thing is, when something goes wrong and you're on your own, there's no one to give you first aid, no one to help you dig your sled out, no one to give you a ride or get help. Riding so aggressively that you're likely to get seriously injured in time, or in poor weather, or dangerous terrain is foolish to my mind, but seldom deadly in a good riding group. Those questionable decisions become much more dangerous riding solo.
