Would you have stayed with L or left? Would you have seen L as someone you could've trusted? What about the concern for your own life?
I'm not sure myself. L shows impressive skills and reasoning (of what he DOES show to the police) but is so reclusive that from what I could tell it'd be a real on-the-fence desicion. The whole risking-my-life thing is very minor as far as I'm concerned. Why would I be on the police force otherwise?
Whelp, that's my take