well, one question, how old were all these people and how recently did these things happen? If your hairdresser was in her 20s, she could have been talking about when she was applying for secondary school, so 10 years ago. Again, the other might be a while ago.
Most 'good' schools will have some people who had a bad experience, and for instance, I've heard my DH talk about schools being good/not good at XYZ based on when he was there, in the last century. People don't accept that schools change.
It was common practice to 'dump those who won't make the grade on someone else's stats" 17 years ago when I did my A levels, most colleges and schools did it unless they couldn't fill their places, but that doesn't mean it's still common practice. Oddly, I have heard people ask others in their 20s who went to schools for their opinion on them, without considering there's unlikely to be the same staff at the school still.
I would look at it yourself and decide whats the best school for your DCs, are they likely to have SEN? If so, then this probably isn't the school for them. That said, a school that's got outstanding provision for SEN can often be the wrong environment for a child without SEN.