At what point does the concept of volens become superceded by clearly criminal activity on a playing field?

We are indebted to Milum for the answer, AW. The key part of the definition he has provided are the words injury relative to that danger. One consents to an injury which one can reasonably foresee.

Some 'rough stuff' is reasonably foreseeable within the rules of the game, but gratuitous or excessive use of force against a player, or attacking anyone who is not a player, is not within the compass of the "volens" maxim. This is true even if "volens" is derived from, and is not itself a latin maxim, as Milum has further elucidated.

A ref is not a player and he has not consented to the risk of injury, AW [at least injury from wilful attack] so I, for one, agree with you. Attacking a ref is a criminal act.

On the other hand, attacking a poster in this forum who wields a term like "volens" with precision, but without understanding its precise historical derivation, is just part of the game. [And I hope it has been as entertaining for others as it has been for me and Milum.]