In many places this can be a very grey area due to laws and sops.
In many places medics and EMTs cannot place pts into protective custody or whatever it may be called in your state.
So even if a pt may not be considered competent and a doc is saying you have to take them.... Until police get there to place a hold... There isn't much you can do.
Disclaimer. Like I mention above it is very important to know the laws and rules of where you work. Also keep in mind bag sops may not always be what is ethically/ morally right.