This happened at least twice this year at Wisconsin home games -- on two 
Saturday nights in a row. Once a linesman, once a referee if I recall. 
In one case, after being attended by the trainer, the official completed 
the period, but did not return for the next period.

The NCAA rule is:

> 32.4 Unable to Continue- Should one of the appointed officials be 
> unable to officiate because of sickness or accident, the remaining 
> officials shall officiate the game. In the two-referee, two-linesman 
> system, if a referee is unable to continue, a one-referee, 
> two-linesman system is recommended. If a linesman is unable to 
> continue, the two-referee, one-linesman system is recommended. In the 
> two-referee, one-linesman system, conferences should establish a 
> policy dealing with this issue.
>
> A conference or supervisor of conference officials is allowed 
> discretion to determine which system to utilize if an official is 
> unable to continue due to injury or illness.
>
> If an on-ice official accidentally leaves the ice or receives an 
> injury that incapacitates the individual from discharging the duties 
> of the job while play is in progress, the game shall be stopped 
> immediately by a remaining on-ice official, unless one of the teams 
> has the puck in a scoring position, in which case the play shall be 
> allowed to be completed. If it is obvious that the injury sustained is 
> of a serious nature, play shall be stopped immediately.

(note that the 3 official system -- 2 referees and 1 linesman is only 
for women's hockey)

   --david

On 3/24/19 5:45 PM, John Edwards wrote:
> In a league tournament situation like that, I would suspect that it's 
> normal for there to be a standby official in place, for just such an 
> emergency. It's less of an issue now that the game starts with four 
> officials. Presumably one or two of officials who worked the 
> semifinal, but didn't work the final, would be the standby refs in 
> this situation.
>
> John
>
> On Sun, Mar 24, 2019 at 5:27 PM Carol White 
> <[log in to unmask] <mailto:[log in to unmask]>> 
> wrote:
>
>     If anyone saw it, the Ref was blindsided by two players at the end
>     of the ice.
>
>     He fell HARD and I think he even hit his head.  The trainer from
>     St Cloud was out there in a flash and he slowly got up.
>
>     They made sure he was okay and when the injured Ref went over to
>     the penalty box area the officials were asking him the Concussion
>     questions.
>
>     There was a spare Ref all dressed and ready to go in case one of
>     them was injured. I found that interesting as I had never heard
>     that before.
>
>     Anyone know if that is standard Operating procedure?  Sounds like
>     a great idea.  The Ref that was injured, stayed in the game and I
>     am sure he has a whale of a headache today.
>
>     Scary!
>
>     Carol
>     GO Gophers!!!
>
>
>
> -- 
> John Edwards
> "You can insure against the weather, but you can't insure against 
> incompetence, can you?" - Phil Tufnell