I'm shattered. I'm on the verge of tears. I was not in Italy. Not at all. That's the story of one man who believes he recognised me. There is no hint of evidence.
If he was in Mexico for almost a month he should be able to prove it. Wouldn't he have receipts for say... lodging, food etc. How about an airline ticket? He didn't swim there! Wouldn't he also have a stamped passport? Since he's in the EU, he wouldn't have a stamp for going to Italy, but he would to go outside the EU.