Repro:
1. Pick Earth Spirit and level up Boulder Smash
2. Place a Stone Remnant between Earth Spirit and any smashable unit
3. Directly target the unit with Boulder Smash

Result: Earth Spirit walks towards the unit as expected, in order to smash it. However, as soon as a Remnant comes within smash range of Earth Spirit, he smashes the remnant instead and stops moving towards the target to smash it.

Expected: When I directly target a unit with Boulder Smash, I expect Earth Spirit to actually cast it on the targeted unit, and not on any nearby remnant. It should only smash remnants when I ground-target the spell.

Here is a very realistic example scenario: Let's say you are on low hp and are followed by an enemy hero. Your only chance to escape is to boulder smash him over a cliff so his path gets drastically increased and you can teleport away. But then there happens to be a stone remnant right next to you as you directly target the enemy hero. Instead of the enemy getting knocked back, the remnant gets smashed. This stuns the enemy for a second and one second is not enough for your 3 second teleport. RIP Earth Spirit.