I have been bitten a number of times - but not always by the same glider.
I had one rescue that bit me every time I offered her a treat - I think she had been teased with food by a previous owner. She was so anxious to get the treat that she would lunge mouth first to grab it and often missed the treat and got a chunk of my finger instead.
Another glider panicked when her nails were being trimmed for the first time at the vets - she bit me several times in the process because I was holding her. I was the one that went home with bandaids on my hands that day.
Other bites have been during nail trimmings or just this evening when one of my sneaky gliders leaped out of the cage when I was putting dinner in the cage and ran right at my little dog. I grabbed her and it startled her so she bit my hand - better that I get bitten than to let her get caught by the dog.
Gliders do have very long sharp front teeth so bites when they do happen can easily draw blood.