Why do people keep calling this MDL landmine incident a "provocation"?

‌A provocation would be North Korea firing missiles into the East Sea
or China and Russia violating the KADIZ with fighter jets
Kim Yo-jong calling this landmine tragedy a staged event is also a provocation
In this incident, North Korea crossed the MDL and planted landmines on our territory—actual live mines
This is an act of aggression.
I don't understand why people keep trying to downplay it by calling it a "provocation."