"The spokeswoman said images recorded by a surveillance camera aboard the bus indicate the driver told a counsellor that he couldn't keep driving unless Izaak's "piercing" outbursts stopped.
The spokeswoman quoted the driver as saying, "I can't drive if that keeps up."
"He said he was concerned that he couldn't continue to drive the bus because it was distracting."
Patterson said the driver did not ask to have the boy removed, and it appeared Izaak and his counsellor left the bus voluntarily."
If you accept the transit authority's position then it still seems likely to me that the counselor would have interpreted the driver's statement as an indication that the boy would have to be removed from the bus since they might not have been able to guarantee he would not continue with the screaming. I do not believe they felt that the boy's continued presence was wanted on the bus.
I am the father of a 13 year old boy with Autistic Disorder. He loves going for drives, even long drives, and is generally quiet and well behaved. There are times though, including yesterday, when his behavior could be described as "distracting". Sometimes he does engage in piercing screams, although they usually subside. Sometimes he pulls my hair or tries to grab my arm. When he does these things he is seated directly behind me; in close proximity. He is closer to me, arms's reach, then a boy on a bus would be to the driver.