In short: yes.
I'm very selective about agreeing to overnight/express shipping for this reason, and I won't do it if there are big storms in the weather forecast. The current storm has been discussed on the news for over a week as forecasters looked ahead to Christmas.
Hopefully your buyer is understanding of the situation and still wants the item even if it's late, but yeah, it's very possible they'll file a claim 'not as described' because the package didn't arrive overnight.