If the player has been spotted by an AI unit,
and has subsequently broken contact and enough time has past for the AI to forgot about the player,
and the AI has line of sight with the player,
then the player's exact position is revealed to the enemy AI when the player sets of a remotely detonated explosive.
Repro with AI having seen then forgotten about the player:
Enemy AI should not know the players exact current location without a plausible detection mechanism (line of sight, sound, etc).
Detonating explosives should make the AI search/look around for the player (as occurs when AI who have never detected the player see explosives going off).
Repro with AI never having seen the player:
Repro with AI still remembering the player: