On frame 1204, the stack of five encryptors (at 22,15) blow up a destructor, creating two new possible shortest paths through the created hole, either left or right around the nearby filters. In the replay the encryptors move to the left (to position (21, 15) on frame 1205), but I think that they should have moved to the right (to 23,15) due to “Pathing Logic Rule 4”: “If there are two tiles with equal distances and are equally prefered based on direction, the unit will choose one that is in the direction of it’s target edge. For example, if a unit wants to reach the top-right edge, and must choose between moving left and right, if both paths have the same minimum number of steps it will move right.”
Second edit:
In the first replay I was looking at the wrong frame (the frame that had a mismatch with my simulator was 2485) and it did indeed move correctly in this frame.
In the second replay it also moves correctly.
I was confused because of the wording of the second rule: “If multiple tiles are equally close to the units destination, move in the opposite direction of the previous movement. For example, if the Unit made a vertical move on its previous step, it will prefer a horizontal move.”
With the example this makes it sound like “opposite” implies to move along a different axis and that the 4th rule acts as a tiebreaker for movement on the same axis.