I realize that claiming a similarity between people with disabilities and Trayvon Martin is potentially volatile and risks overstatement. This is an analogy that I'm still working through, so please bear with me.
One thing the Zimmerman verdict suggests is that young, male African-Americans have a very narrow range of acceptable responses to obnoxious, possibly threatening behavior. If you don't react exactly correctly … if, for instance, you lose your temper and maybe get a little punchy yourself … then it's okay for the other person to kill you. You either show infinite patience and behave absolutely perfectly, or you're toast. I'm no legal expert, but it seems like Trayvon Martin made the "mistake" of confronting the man he probably thought was stalking him or trying to intimidate him. He paid for this rather mild and understandable departure from purely rational behavior with his life.
It's the same for people with disabilities, though not the being killed part. When people with disabilities encounter obnoxious behavior or discrimination from just about anyone, the acceptable reaction is to remain passive, make a joke of it, reassure everyone that "it's okay", or just ignore it. Any other response is met with shock, claims of hurt feelings, and a quickly growing reputation for bitterness and "inappropriateness". When this happens in the context of dealing with any kind of officialdom … human service agencies, housing programs, doctors, teachers, counselors, and government officials … the consequences are worse. We are quickly labeled as either belligerent, mean, noncompliant, or "borderline personality". The exact terms depend on the field involved, but the result is a kind of black-balling that can have massive social and economic effects. We aren't shot like Trayvon Martin, but good luck the next time we try to get a problem resolved, obtain help in a pinch, or even get proper medical attention.