You can tell the difference between a drunken passenger and a dissabled person. For a start when you book a flight and request assistance, the airline/handling agent are made aware of this. 90% of dissabled passengers or passengers with special needs request a seat towards the front of the aircraft (charter aircraft). These passengers also have a comment put next to thier name to inform the crew about thier needs/requests and to allow the gate staff to locate them early for pre-boarding.
Now if someone came towards me singing, falling over about the place, being abusive etc, etc I would be 100% sure that they were pissed and sould be off loaded.
If you read the posts made by various ppruners (instead of jumping to conclusions) you would read how we identifiy drunken passengers. If we did question a dissabled passenger, I'm sure the person traveling with them would inform us of their dissability.
From the tone of your post, its sounds like you have been offloaded because you were intoxicated.