Remedies: 1. The opponent whose private information it is may decide whether to take involved cards in the now-known private information and re-randomize them with the original randomized source of appropriate cards. 2. If they decide not to, instruct the players to proceed.
§ 702.11.b Tournament Rules PDF (officieel)
§ 702 Game Play Errors
§ 702.11 Looking at Opponent Private Information [Warning]: A player accidentally looks at information that is private to their opponent. See CR 128. Privacy for information types.