Blocks can be broken one block beyond range upward

Blocks can be destroyed one block higher than the range vertically by jumping repeatedly.

Damage value doesn't reset when action is ceased, so when another jump is performed, more damage is caused.

Can be recreated with tall trees:

Stand directly under the column of blocks you want to destroy. chop with hand or axe until the top blocks are out of range, then hold jump key. The block will be slowly destroyed.