HS Stats don't mean much and it won't take long on this site to find that out.
For example, a single 3-4 in a 12 game sample distorts the numbers. Assume about 40 AB's and in the other 36 has 12 hits for .333 BA. Add in the 3-4 and you are at .400. If it came against bad pitching even more so.
Hitting .300 in HS isn't that big of a deal. Then there is this...who's keeping the book? Change a few errors into hits and you get crazy stuff.