Great result, that - so all kids with ADHD are disadvantaged against their NT peers rather than just some of them (said as parent with ADHD with child with ADHD).
Think if this was tested in law it could prove to be a failure to make a reasonable adjustment. Of course EA2010 does not require everyone with the same condition,
to have the same evidence, before anyone can get an adjustment.
But that's working on the basis that extra time is a reasonable adjustment for someone with ADHD. That's not how it works. The diagnosis is irrelevant: it's the need that matters.
Access arrangements must be made in line with regular classroom practice. If a child regularly needs additional time on work in lessons because they, for example, have difficulties processing information within questions/tasks, even when the information is there in front of them to refer back to, then they are likely to qualify for extra time in exams. This will all need to be evidenced. It doesn't matter if this child has a diagnosis to go with their difficulties or not.
Conversely, if a child has an ADHD diagnosis but does not require extra time during lessons to adequately complete the tasks/questions, they wouldn't qualify because it's not something they need as part of regular schooling. There may, however, be other arrangements that are needed.
The issue comes from people assuming all children with X condition need Y access arrangement. That's just simply untrue. It's child specific. EPs (and others) put it in their reports as recommendations purely so they can make a long list of possible recommendations but those words hold no weight if it's not actually what that child needs in class.