Depends on how they look.
Any stridor, difficulty speaking, lingering cough goes in to the ER. Much stridor or difficulty speaking means I'm prepared to manage the airway in case things deteriorate.
No problems at all? No cough, normal vital signs, clear lung sounds and no stridor? If they don't want to go that's ok with me.
Also the reason for the choking is another thing I assess: is there an underlying swallowing problem? Something neuro going on? If its a kid, was there a neglect issue?
If someone did abdominal thrusts, is there any trauma from that? Abdominal exam ok? If they are very young or very old, I would be more suspicious.