Are there studies showing that most pedophiles have a "normal" appearance? I am unaware.
If they all looked weird and creepy, the amount of sex crimes wouldn't be so high. Everyone would know what to watch for.
Moreover, if you're a criminal, you don't want to be caught. So, it's not in your best interest to look weird and creepy. And considering a lot of sex offenders are repeat offenders ... they obviously gain repeated access to children. And it's probably not by being weird and creepy, while rousing the suspicion of adults.
Now, I'm sure there is a small number of them who can't blend in. And maybe this guy was one of them. Maybe not. We'll never know. But, either way, after living for so long in America, I'm on the side of the OP - it's always better to be safe than sorry, especially when it comes to children.