I think its the hand wipes, as they do contain alcohol- but clearly he could see you were over 18, or even 21 so shouldnt have mattered.The shopping delivery i ordered near beginning of lockdown did this to us- because id ordered antibac wipes- i was on way back from hospital (i still had to have blood tests done regular for warfarin) my son came to pick me up, leaving his brother, almost 17, at home) i knew I'd be back for shopping time I'd requested, We dont live far from hosp, but Asda shop arrived early and they wouldnt leave any of it- i rang as i knew i hadnt bought any booze- & they explained it was because of the alcohol in the antibac wipes! They couldnt leave the shop with my younger son! Crazy i know! (I pointed out he'd have had to suck a heck of a lot of wipes to get drunk!)
Or they could've left rest of shop, and not the wipes! Just like they could have left you the bath mat! 