Scott Roberts
EF2
[Hmm...this also makes me wonder about a chaser's liability from helping out if someone dies or something similar and tries to blame the chaser)]
I haven't read the rest of the thread before posting this, so it may be somewhere else...
One of the first things we were taught in EMT class is the "Good Samaritan" doctrine. If you are making your best efforts to help, within the limits of your training (or lack of training), you are not liable for the outcome of your actions.
The key is in only doing what you know how to do. If a person has a heart attack after you help them out of their basement, you aren't liable. If you don't know basic first aid and try to splint an injury, you may be in a legal grey area, but Good Samaritan laws (or common law in a lot of cases) would likely still cover you.
Just don't hold yourself out as knowing things you don't -- i.e. don't tell someone it's safe to go back in their house and look for Fluffy. Unless you're a structural engineer, you probably don't have the knowledge to make that determination.