QA-APP-2: When multiple violations have occurred on a single throw, how do I determine which rule was first violated, given that a rule has not been violated until the disc has come to rest?

The meaning of “first” in the rule is the common understanding of when the disc first enters a state where it is in violation of a rule. One common pair of rules that can be violated during a single throw are OB and Mandatory. In that case, you would compare when the disc last crossed into OB with when it crossed the mandatory line, and play whichever happened first.