My First funny Primary school story :D

My middle son, my dd and I walked down to the bus stop...waited....and waited...waited for about an hour...my son is now 1/2 hour late coming home on the bus. Almost thinking of going home to get the van and come back to wait...but I didn't want to miss the bus so I stayed. Next, thing the bus comes around the corner, my oldest gets off the bus and the driver apologizes about being late. He tells me they couldn't get the side bus door open so they had to transfer all the kids onto another bus...then I notice my son has a book in his hand that I know isn't ours and I think to myself well it is probably one he borrowed from the library or a friend.
We start walking home, I ask him where he got the book from, he says " There was a book fair at school today and our class went over to the other school to see it. That is where I got the book from!" I said "Oh, I see and did you pay for this book??" Just as I said that I saw that the book was stamped, which meant that it was paid for...which then made me wonder how he got this book since I hadn't given him the money. He then said that his dude's mom got him this book, so I asked him if she said anything to him about paying her back, or if there was a note from the teacher in his bag about this book. He said "nope, my dude's mom said nothing and no note either mommy! "
I then hurry home, start wondering what I should do about this...so I made the mother of my son's dude one of my handmade greeting cards (forgot to take a picture I am sorry... tonight was kind of crazy...will make one like it and post it for you). I goto my sons parent teacher night, ask his teacher and the supposid teacher of this other little boy what happened. They both said that they didn't know who it was who had bought my son the book, but that they had heard all about this several times. The teachers didn't even know who this child was (now I am thinking perhaps it was an imaginary friend of somesort...which he hasn't had for awhile), but the teacher took my card and said she would look into it for me. I will keep you posted on this story...what would you have done if this had happened to you??
In someways I feel sort of guilty about this other mom (whom I don't know) getting my son a book (I start to think may be he was crying and this mom felt bad for him so she got him the book), I feel appreciative that she did that for him. I also sort of feel awkward, mainly because you never know how one may act when getting the re-payment...some people would thank you for paying them back, some might take offence to it. Anyways, enough rambling from me...have a great night :D!