Delta should pay to fix it if you filed a baggage damage report.
I don't really have anything to add here, but I'm curious if I'm missing something. Is the fact that the bag was a 1MM gift relevant? Does delta really make such a distinction when deciding how to handle a damage incident?
It matters in regard to warranty. For example in the hartmann link above, it states "Coverage under the 2 Year Limited Warranty requires a retailer receipt as proof of purchase." Not sure how the 1MM gift works in this instance.