Bad news about your friends crash, it's awful when that happens.

However, stuff breaks. It's all just a matter of when. Things high on the list of things you'd rather not break are as you point out - forks and seatposts.

No point in speculating who's to blame or arguing that stuff like this shouldn't happen, the bottom line is is that racing components push the boundaries of what's possible and carbon especially has a pretty nasty mode of failure. 1+1=2, and sometimes stuff like this is going to happen.

It's half the reason I use a Thomson layback seatpost and True Temper AlphaQ X2 tandem forks.