According to the Wikipedia entry, in the initial incident they were just trimming the tree, not cutting it down.
Trimming the tree in one of the world's most fraught DMZ, is still going to affect sight lines, so framing it as an "innocent gardening job" elides the truth.
Not trimming the tree also affects sight lines, because trees are living things that grow.
No one framed it as "innocent".
I mean, it was a tree removal. They just don't typically involve B-52s, fighter cover, and an aircraft carrier battle group.