IMO one the most mandatory items one should have is an avalung, I know now the difference it may have made, thankfully no one needed one, but very apparent how that device could save lives. I have worn one for years.
Moreover, it now becomes obvious that having an airbag is not always a good thing, I will always be watching run out areas now, if airbag deployed, where will it take me? into trees? rocks? over cliffs? there may be times where not deploying the airbag is better choice,(only if you have an avalung). Many studies show that subjects have been able to breathe up to 60 minutes with an avalung. That is incredible.
This is device I thought of, but see now it exists in germany,
http://www.lawinenball.com/English Home.htm
Also, I have be re-reading my favorite book by Bruce Tremper called "staying alive in avalanche terrain". Chapter 10 now hits home very, very hard. It is all about the "human factor", how people behave in groups, how decisions are made, when and how we cross our own lines, how we see what we want to see, false confidence etc. Its all about the human factor more than any other thing. who do you ride with? do the have the good equiptment? do they really know how to use it? or do they have an old SOS unit? Are they in shape? would they fight to save you? how hard?
the lessons learnt for me with this event are insurmountable, I have been riding for 17 years in the backcounty and have never been this close to catastrophe. It is lesson I appreciate to its fullest, it will change many things about how I ride and some of the equipment we will have.