Not a lie in the contract world its called "Forced Majure" beyond there control but did everything possible to meet it.
I'm not saying the contract stated a lie. I have doubts that a specified delivery date was even in the contract (may or may not have been there not disputing the fact either way) but Merriam Webster lie 1. b." an untrue or inaccurate statement that may or may not be believed true by the speaker or writer. " they believed that they could fulfill orders accordingll to the deadline but that proved untrue making it a lie.