I think the message is to change your environment such that you're not getting this sort of interruption.

I interviewed, three times (and turned down, three times) with a firm that apparently really wanted me. Why?

1: They were a very small vendor working for a very large client. The client is a household (swear) word, and behaves in a gratuitously overbearing manner to its customers and other vendors.

2: Everyone I spoke with admitted that this relationship lead to many, many last-minute changes in spec requiring much overtime and pain to make things just so. All while praying that things wouldn't change yet again at the next last minute.

I said "thanks, but no".