Most likely a slight oversight, but when entering a match already in progress if the bot/player took damage and you join in to replace them you will not have full health. I completed the mission without taking any melee damage and was not able to unlock the penance. (Done on consignment yard hl17-36)
Regardless of what health you had when you join a mission, if you’re not in there from beginning to end, it is impossible to complete this penance, or penances like this. This is to avoid abuse by reconnecting (or just plain joining) at the end of matches for an easy completion.
I understand and thank you for clearing that up for me. One thing I would like to mention was I joined in a mission in progress (not through quickplay) and was there from start to finish only “missing” the portion you run from the drop ship to the start of combat. While not being a huge issue it’s still a bummer to play 95% of the mission successfully and be shorthanded a penance due to abuse prevention.