I had a similar problem going to LGA from MIA.

I went to Orlando for the weekend (driving) and had packed my regular sized toothpaste. I forgot it was there.

I flew MIA-LGA several weeks later - no problem. I cleared security in LGA for my return trip to MIA - no problem. When my MIA flight was delayed 2+ hrs I decided to go to food court for a bite to eat. When I went through security (Now the 3rd time), the TSA spotted it gave me a lecture about. I said I forgot it and told them to keep it.

Funny thing is that it cleared twice, one of the times the same LGA checkpoint.

Goes to show just how useful they are.