Realizing this is all speculation, but if you're willing to divert or turn an aircraft around due to an unruly passenger because you're afraid or concerned about what they MIGHT do then you'd better secure them to a seat. And if you have them secured to a seat, then carry on to the destination and not disrupt 200+ other passengers. Get unruly, get handcuffed, zip tied, or taped to a seat until the aircraft lands. Their choice.