I have friends who had a little girl who was actually diagnosed; after a year or so of speech/tactile therapy, they, um, changed their minds. (Of course, none of us who knew the young lady believed the diagnosis in the first place.)

You know your own kid best, so if your intuition is telling you that he's fine, he probably is. Care providers are more sensitive now because the earlier the intervention, the more helpful it's likely to be, but that means more false positives.