Once, while waiting for the lift on the handicapped line with my son, my husband was questioned by a CM as to WHY my son needed to ride it (the rest of the family, 4 people, walked up the hill). He said to my husband "he does not look all that handicapped to ME". (He has down syndrome, autism, and had both ankles fused 9 months earlier-- he only came to the water park for a couple of hours).
My husband did complain, and they pulled the CM to another location for that day. They also said they would "re-train" him, which is really the best possible thing.
This was about 5 years ago.