It was my first time ordering gluten-free cheeseburgers there, I've never tried it at McDonald's before.
I even stood in line at the counter and said it again.
After eating I looked at the bill again and it didn't say anything about gluten-free!
Back at the counter I asked again and it turned out that they were completely normal cheeseburgers.
I have to strongly advise anyone with gluten intolerance not to eat there.
And if you do, then do better than I did and check your bill before eating.
The employee there didn't really care about the whole thing.