Our animals have all acted funny whenever one of my family members has had to go to the hospital. I think it's similar to when you're feeling particularly craptacular (either due to emotions or illness or just the blues) and they almost always come to be with you. At least that's my experience with my animals. If I had my guess which is similar to yours is that your hammie picked up on a general 'not rightness' about you and is showing his concern. Or it could be a lingering smell from the hospital stuff or any medicines or treatment they used on or near you. My cats act really funny for days when I or my mother come back from the hospital.
Ouch, glass in the foot is not pleasant. Good luck with your surgery.
