5 days Mose definitely pushes into the category of "unreasonable".
By who's standards? Shouldn't you state your expectations if you are not flexible?
Example of a trusted forum members auctions that sets proper expectations: https://bitcointalksearch.org/topic/m.17089720
Everyone making auctions should set their expectations properly or be flexible with a party willing to pay.
Looking at the auction it also does not state that tman has to honor any bid, so if you are to be correct about your statement that also means that this would be correct.
I have to agree. Unless otherwise stated or negotiated beforehand, a bid should be considered as a good faith commitment to pay that amount shortly after the auction ends. IMHO the exchange rate is too volatile right now for extended grace periods on payment.