Final answer:
Typically, if a goal is scored and not seen by the Referee, the Linesman informs the Referee of what they observed. The Referee then decides whether to award the goal, potentially using video replay if league rules permit.
Step-by-step explanation:
The procedure that the Linesman employs when a goal is scored, and it is not observed by the Referee, can vary depending on the rules of the specific ice hockey league. However, generally speaking, if the Referee did not see the goal, the Linesman can report what they witnessed to the Referee, who will then make the final decision. In some leagues, the Linesman may have the authority to call goals, but in many cases, they can only advise the Referee. If the goal is clear and undeniable, and all other protocols are followed, the goal is usually awarded. In professional leagues like the NHL, there is also a possibility for the play to be reviewed by off-ice officials or via video replay if the technology and league rules allow.