Pale oak trees with creaking hearts (and probably regular ones too) do not generate with perfect symmetry when it comes to possible positions of leaves.

Attached are two screenshots, a mass of all possible locations that pale oak leaves can generate when a tree is created, and a version that reconstructed with wool for added clarity (black=4 block column, brown=5, red=6, orange=7)

To observe, create a chain of command blocks going upward (first repeating, rest chain), activate it, then tick sprint a few days. Commands marked with # are ones I used that should not be necessary to achieve the effect

fill ~4 ~-10 ~4 ~16 ~12 ~16 air
place feature minecraft:pale_oak_creaking ~10 ~ ~10
clone ~5 ~-1 ~5 ~15 ~10 ~15 ~20 ~-1 ~5 filtered minecraft:creaking_heart
clone ~5 ~-1 ~5 ~15 ~10 ~15 ~5 ~-1 ~20 filtered minecraft:pale_oak_log
clone ~5 ~-1 ~5 ~15 ~10 ~15 ~20 ~-1 ~20 filtered minecraft:pale_oak_leaves
fill ~19 ~-5 ~19 ~31 ~5 ~31 pale_oak_leaves[persistent=true] replace minecraft:pale_oak_leaves[persistent=false]
kill @e[type=item]