A and B

1 - A falls off of B's roof while fixing B's roof.
2 - B walks by A, A's homeless, and asks for money, B walks away.
3 - A needs to go somewhere, he doesn't have a car, B lends his car, no brakes, A crashes.
4 - B has swine flu, goes to school, and gives it to A.

1. In a legal manner it is B's fault because A was on his roof/property and therefore he is responsible to whatever happens to A.

2. Its not B's responsibility to give his hard earned money to A. B works for the money while A just begs for someone else's hard earned money.

3. B gave him a car and we don't know whether he knew if the breaks where broken or not. If he did know they were broken, then its his fault but other than that its A's fault for not inspecting/testing it.

4. Its not B's fault because he might not know he has it because the effects show after 2 days, not straight away.