The dangerous n00b thread got me thinking about when to intervene when you see something really bad happening. For example, one poster describes a guy belaying his kid at a climbing wall - kid gets to the top and traverses all along the top of the wall until dad tells him to let go. Kid lets go, takes a terrible swing and bashes his head. I wonder, why didn't the observer step in?
Then again, I've seen a lot of scenarios that seem really bad, and in my opinion, you often up your own danger level the minute you get involved. Case in point:
J-tree a few years back. The couple next to me was a military boy ~19y.o. and his girlfriend. You've all seen the type - he likes climbing, she likes him - that's the only reason she's out here tied in. When I arrive he's preparing to belay her from the top of the climb, and at the same time trying to shout down instructions for her to tie in - she's forgotten how to tie the knot, and he's dumb enough to think he can explain it from up there. Instead, she is just getting more and more confused. I graciously ask if she'd like a hand, and she accepts.
Okay, so it's a typical 5.7 j-tree climb - a combination of smearing on slabs and jams in flaring cracks, and her sneakers just aren't cutting it. She's having a miserable time, and he's trying to convince her that she isn't. Bad scene.
Fast forward 30 minutes... I led my climb, and I'm just scrambling onto the topout looking for something to anchor into. Meanwhile, she's now anchored at the top, belaying him up on the next climb over, maybe ten feet away. He falls, and her belay fails. He slips/backpedals the 15-20 feet back down the slab and slams into my belayer, knocking him over. Only luck kept my belayer from pulling me off the top - and had he done so, it's very unlikely he would have stopped me before I cratered.
I've also helped out where everything went fine. But... looking back on most of those, it always would've been safer to have just moved on.