So, the second tester was a school-paid tester? Just wondering, because it does seem like there are discrepancies sometimes between private and school. You could go all directions with that observations, of course.
But that's a huge gap. What does your DS say about the testing? I'm assuming your gut is that the second test is wrong? I do think it would be quite interesting to have the two testers talk to each other.
I honestly wonder what we would see if all our kids were retested at least once. A friend recently had her child retested and he came out not gifted after testing over 130 in K. Another friend retested and the child who came out as not gifted in 1st or maybe second now tests as gifted. In both cases, it was not the same test or tester, but a "legit" test and tester. However, I think we are talking about a 15-20 point gap, so not as extreme as what you got.
ETA: Just remembered ANOTHER friend who retested and got gifted results after "not gifted" the first time--in that case, first test was a private psych and second test was a school psych. That child is obviously gifted. I have no doubt. I don't know what happened the first time.