Attempting to place ladders or torches on the side face of packed grass results in them being placed on any non-air, non-packed grass, face available (if any).

In first pic, ladder is being placed on opposite side of the air block the ladder occupies.

Attempted from both above and below (in the moat/ditch pictured) with same results. Breaking the ladder and re-attempting results in same behavior.

Cross-hairs are on block-side ladders were being placed ("Attempted"). You can see the ladders are actually added to the opposite side ("Result").

In second screenshot I tried a few torch placements. Placing them on "far" side of ditch results in any non-air/grass-block side being chosen. Before I took this they were being placed on an adjacent side. When I dug ditch to be three wide to remove side grass, the top of the center block was chosen.

If I remove the center dirt block from the ditch then I cannot place a torch while cross-hairs are on the packed grass block.