When does designated bench personnel become the HC following DQ of the HC?

[La Rikardo]

Since we have explicitly-defined definitions regarding what it means to be a player, substitute, bench personnel, team member, etc., it seems odd that there is nothing in the rules to define what it means to be the head coach given that the term "head coach" appears (by my count using the online search function) 49 times in the rule book. It's a meaningful role, yet we have no instruction regarding what exactly the term means.

Though my OP situation may be far-fetched, head coaches are disqualified pretty frequently, but we have no rule basis regarding how that situation should be handled with regard to a new head coach. Many of the rules of this game hinge on technical definitions and this is a pretty large vacancy in that sense.

I agree with Adam that we should require an adult bench personnel to act as head coach at all times. Here's my idea for how this could be handled in the rules:

Each team must name a head coach on the roster. This head coach will remain the head coach unless he is unable to continue in his role. If he is unable to continue in his role, an individual must be immediately named to replace him. He continues to be the head coach until the referee asks that a replacement head coach be named, at which point the person named becomes the head coach.

If the replacement head coach had been charged with a technical foul previously in the game, he will lose coaching-box privileges. If any head coach loses coaching-box privileges at any time, coaching-box privileges are lost for his team for the remainder of the game.