Sports news television coverage of the Utah/BYU football game also showed the referees being pelted by objects as they left the field at the conclusion of the game.
Local officials in Provo declared their intent to identify the offenders and deal with them appropriately. Ridiculous. The miscreants were probably either intellectually juvenile or bolstered by their favorite beverage which further exaggerated their childish behavior.
However, since officials are assigned by the NCAA, governing authority for collegiate sports, it is up to that body to assess BYU a fine for lack of appropriate security at the entry and access portals. Having managed major sports facilities for years, I never allowed such exit surroundings to be unguarded from emotionally erratic or maturity-challenged hotheaded fans, following their Neanderthal tendencies. And the monetary fine needs to be fairly substantive.