Snickers?

I had a craving for chocolate yesterday - which is actually pretty rare for me, I would much rather indulge in a chip of any kind - so I paid a visit to the vending machine and got a Snickers.... And a little while later, felt glutened! Ugh, I felt gross for a few hours...

What the heck, i thought Snickers were gluten free? Anyone else have this? I'm just going to avoid them from now on I guess.