With the new update to DDLP there exists a strange scenario whereby a sideboard card can become revealed to both players at the same time (e.g. Goblin Guide attacking, a Clash card being played).
The policy specifies that "(or is about to see it)“ however I feel like this is to prevent advantage gained by being tight-lipped until the game (a discard spell etc) forces the player committing the infraction to reveal it.
This also brings up the question of a discovery made during a ”Mindslaver" turn.

Basically I think there needs to be clarification regarding an instance where a player with a sideboard card discovers it but this also comes at the same time as an opponent would see it.

Thank you for the insight, Lachlan; I'll make sure the Policy team sees and considers your input!

d:^D