Yep defensive riding can avoid lots of accidents while on a motorbike but its very hard to behave sometimes. I find if I leave work pissed off I tend to ride home very aggressively and this is when the bad shit happens. Ive also had 2 crashes in the past 2 years coming from from work which is a 3km commute. Also certain times of the day/year can be worse then other times. I find christmas/easter bad with pissed off cagers and after work. Most of the time its the people around you which cause the problems. 2 weeks ago I had a minor crash when a car changed lanes without noticing me so I slammed on the front brakes, locked up and low slided.
I found on my old bike when I had a 110db exhaust on it I never had any near misses anymore but on my new bike it happens all the time especially from people who decide to cut infront of you without any blinkers. I wont ride without full leathers from now on because of the impact protection they provide. Both my accidents I had kevlar jeans on but they just dont cut it even at low speeds.
Sorry to hear about your off hope you get better.