Is this proof that Santa Claus is real?

I have two children: a 16 year old daughter and a 17 year old son. They both stopped believing in Santa Claus when they were 12 and then my husband and I decided not to buy them any more "Santa gifts". Then one day, last year, we didn't have enough time to buy the kids lots of presents, because Christmas kind of snuck up on us last year. But, on Christmas morning, the kids woke up and saw 2 presents for each of them that my husband and I do not recall buying. When my daughter opened them up they were a laptop and an iTouch. When my son opened his up, he saw a note that said "Go to the garage to see your present", and when he went there was a brand in' new mountain bike, which is what he was asking for the entire year. His other gift was a blackberry storm. My husband and I told the kids that we bought them, but then we were wondering about it the entire day. We never bought them any of those things that they received, so does that mean Santa Claus exists?