A rip in time to a parallel universe?

My 3 1/2 year old son was playing in the corner of our living room yesterday morning, squatting over his Legos.  He was still in his pajamas, which include a diaper, when he called out that he wanted to put his "morning clothes" on.   As I went to pick him up, I noticed a small puddle under him.  I touched his pants, he was dry.  I felt his legs; they were dry, too.  Being a mom, I stuck my finger in the puddle and smelled it.  It was indeed urine, but the boy was completely dry.  I asked him if he peed there and he said no.  

I carried the boy into his room, helped him get dressed and then followed him to the kitchen as he ran to get paper towels.  In the 4 minutes that we were away from the puddle, it vanished.  Completely gone.  No trace of moisture, no scent of urine.

No one else was home and it couldn't have evaporated.  The boy has witnessed the small puddle and, too, wondered where it had gone.  And although there are many a times that I have placed wishes for these kind of messes to go away on their own, it's a little freaky when it actually happens.