Sounds like due to an injury while in velvet. Often, bucks break a tine or main beam, but the velvet acts like a sock or splint and holds it together, so it mends in the broken/bent way. This also accounts for most "club" antlers, where a big ball forms at the tip of a tine or broken beam, under velvet. Genetic nontypicals are generally more symmetrical and account for the "freaks" with large numbers of weird tines. They're all far more interesting than mill-run "perfect" antlers, I think.