Considering the on field penalty is the not the first level of sanction, I feel the officials won't (or shouldn't) be responsible for noticing and calling it. Some off field administration would be responsible for addressing the first infraction and warning game day administration. If it continues, then I would assume they'd buzz down over radios or replay to tell the officials to enforce the penalty.
There's no way the on field officials will have the authority to issue $100k fines (or more), which they would have to do before it escalates to 15 yard penalty.