Of course it was an accident unless the soldier was attempting to bank the bullet off the ground to ricochet into the medic

NY Times:

A Day, a Life: When a Medic Was Killed in Gaza, Was It an Accident?

When an Israeli soldier killed Rouzan al-Najjar, Palestinians called her an innocent martyr. Israel portrayed her as a threat. The truth is more complicated.

I don't know of any troops who deliberately fire into the ground with the intent to kill someone.  It would not surprise me that in Gaza the Palestinians put someone deliberately in a position where they might be killed while to cover for terrorist operations.