ACBL Conditions of Contest are online at
http://www.acbl.org/details.asp?id=1829&PID=9918The ACBL regs for Swiss Teams, at least, are similar to the German regulations posted. They don't speak to "acts of God" per se, but do say that a TD can ignore or modify the penalty/disqualification provisions "if compelling reasons exist".
I don't know of any case law involving this question.