Isn't it odd?

A few weeks ago when Frank and I returned from vacation, we were down in the laundry room at 10:00am getting things out of the washers when a fellow tenant came in to inquire if we had an emergency contact number for our building managers. The tenant had accidentally locked himself out of his 10th floor apartment, but the only phone # we have for management is their home phone number. I never gave it a second thought until about 8:30 pm when I was out on my balcony watering my plants and I happened to look down and see this same tenant sitting on the front steps leading to the lobby. I pointed him out to Frank who went to talk to the guy, and he had been calling management all day with no reply, and his pregnant wife and 2 sons were in the park across the street trying to stay occupied. Well, we invited them in of course, made some drinks & snacks, put on a kids movie and dug out the small collection of toys we had, and by 10:30pm with still no word from management, we brought out the extra sheets/pillows/blankets and made up the futon and guest bed, doled out some t-shirts to ware as jammies, dug out the spare toothbrushes we had in the bathroom cabinet and called it a night with 4 strangers in the living room and guest room. No problem, glad we could help, after all, we couldn't let a pregnant lady and 2 small kids stay outside all night! They just moved here form the stares a few months ago and have no family here, each parent thought the other had grabbed the keys, and all they had were the car keys...but the key to remove The Club" was locked inside their apartment with the house keys. The next morning we dolled out breakfast/coffee and morning cartoons, and by 9:30am someone had shown up to open the door of the family's apartment for them.
The odd part comes from the fact that we have not seen/herd from them since. Huh. No phone call to say "Thanks again", and no thank you card. . Its not a big deal at all, but if it were me crashing at a total strangers place I would have at the very least gone out to replace the toothbrushes and give a thank-you card, am I wrong??