By Tzvi Machlin Billionaire Daryl Katz has been the owner of the NHL’s Edmonton Oilers for nearly 15 years now. But he’s facing troubling allegations that could lead to serious legal problems. On Thursday, court filings alleged that Katz paid $75,000 to a then-underage girl for sex. He has been listed as a third-party defendant in a U.S. District Court in Nevada. The filings came as part of a counterclaim in response to a lawsuit filed against a dance teacher accused of sexual abuse. That counterclaim alleged that Katz paid a 17-year-old ballerina for sex. Katz is one of three men being accuse…