1. Where does anyone see blood on that dagger? Before I even thought about rezzing I noticed it was particularly clean.
2. If you could use tissue shed before death for a rez, disintegrate would do nothing to prevent it. Go back to the last room they stayed in and find a toenail clipping. You could rez anyone, body or no body. Nale was not dead when the (invisible) blood was left on the dagger.

Honestly, I was so sick of Nale, and he got a good, dramatic death. What more could an NPC want?