In Labyrinth Lord, when there is a possibility of surprise for both PCs and foes, both sides roll 1d6. A 1-2 indicates that side is surprised for the first round. If both sides roll a 1-2, both sides are surprised for the first round. A surprised side can take no action.
This is a nice simple and symmetrical rule, but unless there is a third party involved or an ongoing menace (e.g. the room is on fire) I'm at a loss as to the significance. From my point of view it is identical to a situation where no surprise occurred. You could amuse the players with a description of both sides staring agape at each other before melee is joined. But I'm curious if I'm missing something and there is any rule effect that could arise from both sides being surprised.
So has anyone had this situation occur and can describe how this affected the outcome of the following encounter in a rules related fashion (i.e. not just in the narrative color).