I think the OP has already made the decision not to follow up on the offer, and given those particular circumstances, that seems right.
Tweak the scenario a bit, though–and you might make a different decision. Example:
When DD was applying to colleges, a business colleague of DH offered to write her a letter for Wash U. He had been a prominent guy in the US govt and was very active as a Wash U alum. He knew DH well but had never met DD.
We thought just what many posters have said: Maybe this was a bad idea and would backfire on DD. Plus we would have to make a special trip to DC so she could meet him. Still, we asked DD’s college counsellor and he said to go ahead.
DD had been planning to apply to WashU RD, and her counsellor had pointed out that no one from her school had been accepted RD to WashU for the past several years. ED yes, but not RD. (Yield protection? Who knows.) Counsellor told us that a letter from the colleague would have one good effect–it would get her file flagged and keep it out of the “WL or deny everyone from this school” pile.
So we took DD to DC–and did a tour of GWU to make the trip worthwhile no matter what–and she had her interview. He looked at her resume, checked her stats, etc. and conducted a pretty standard, thorough interview. Said he’d be delighted to write her a recommendation to WashU. Then–out of nowhere–he asked whether she was looking at his UG alma mater, a top LAC? Said he’d write her a letter for that school as well. DD didn’t quite know what to say to this; she was not interested in LACs at all.
Anyway, she ended up applying to WashU ED2, and was admitted. Did the letter help? No way to know. College counsellor thought that applying ED was the crucial factor, given that her application was strong on all fronts.
Later on the college counselling department at her school had what they called a ‘come to Jesus’ meeting with the Wash U admissions people and told them that if they continued to admit NO ONE RD the counsellors would start recommending that their students not apply to Wash U anymore RD. Not surprisingly, they admitted a few people RD that year, and in future years.