Date trap - how would you handle this?

This is about dating. The parties (M/F, F/F, M/M) don't matter.

There is a person who likes you. You have done nothing to reciprocate this interest, but you are cordial. They then toss out "What are you doing on (specific date 3 months in the future)?" You fumble, as in I don't know, and then hear "Good, I've got tickets to this event." (very, very cheap function and not a concert). This person once even called a sibling's place of work they didn't even know looking for me. Why, I don't know? It didn't make sense. Ugh.

I didn't like this. I thought it was devious. I sent back the ticket 2 weeks prior to the event, together with a note that a friend from far away was coming to town and I had to show him around. I never heard from this person again. I think it was a little rude, and possibly even cowardly, but I wouldn't entrap someone to going out or associating with me.

Have you had this happen? What would you do if this had happened to you? What do you think was, or is, the correct thing to do?

 

Ok, I don't feel so bad. I didn't want to be asked in the first place and I hated to weasel my way out, but I saw no point in confronting or hurting feelings. My sibling was sort of irritated and amused, more so than mad, but found it weird.