It’s possible they were the MHHI class, so each kid had a secondary diagnosis, from autism, which could be mild, to dyslexia. If that were that case, they may have been taking the medals because of just a couple of kids.
Usually disabilities multiply-- when you are Deaf, having a severe vision impairment, autism, or something, is multiplicatory, but sometimes not, especially when the second impairment is something like CP that mostly affects the lower half of a person body, but doesn’t interfere with signing, then they are just additive. Deafness and dyslexia are generally speaking, multiplicatory, because it interferes with a channel a person can use to communicate with non-signers, but in a special environment, like a Deaf school, it’s more additive.
There may have been several kids there with some serious combinations of disabilities, but a few who happened to have combinations that didn’t interfere with the tasks at hand, like Deafness and dyslexia, or Deafness and mild autism.
The thing is, the type of job the competition prepares these kids for is what MHHI kids realistically need to prepare for. A Deaf person who is functionally illiterate can at best aspire to cleaning motels, stocking shelves, or busing tables. Some of them might be very bright, and pick up the jobs way faster than other people, but their neuro-untypicalities hold them back.
Anyway, if the OP thinks back, probably it wasn’t the whole Deaf team taking the medals. It was probably a few kids on the team carrying a disproportionate about of the weight.
The competition may need a rule that if an individual wins more than n events in a year, they have to retire from the competition, or if they have first, second and third place awards, assign points (3 for first, etc.) and retire competitors who earn more than n points. That gets rid of the ringers.
I means, the Deaf school should be allowed to field a team, and there probably already is a rule that a student has to have a secondary diagnosis, or spent a certain amount of time in resource, or remedial or self-contained classes.
But if there isn’t, there should be, and your nephew’s parents should say something.
I have worked with both normal Deaf people (I went to Gallaudet University for a year to learn ASL so I could become an interpreter), and I have worked with very disabled people when I did community living services. I don’t know a Deaf person who would want to be mistaken for a low-functioning autistic, even for the sake of taking a bunch of medals.