I believe my two title questions are the same (are they?):
Heretofore, what is the longest chain of orphan blocks (of N blocks), such that if someone didn't wait for N+1 confirmations, they may have assumed transactions to be completed when they were not.
For example, on the wiki's blockchain article, it shows orphan chains of two blocks (N=2). In this case, 3 confirmations would have sufficed to confirm transaction with absolute accuracy. https://en.bitcoin.it/wiki/File:Blockchain.png
I ask because it seems 120 confirmations is the gold standard, if you will, as generated bitcoins take that long to confirm. Most other transactions are considered irrevocable at 6 blocks, but what has been the minimum, thus far?
PS. Is this question even answerable!?