On the LAST boss on a 5 man instance, a ninja can wait until everyone else leaves the party except the person who legitimately needed the boss loot. (at this point there are only 2 people in the party) Then the ninja rolls, and leaves the party asap. The roll result happens instantly and the ninja likely has left the party before the other person fully reads the roll results and can comprehend what just happened Then how does a person report that ninja? (At this point there is no party and thus no "healer or dps or tank roll icons" to take evidence pictures of)
What valid evidence is there at that point to report the ninja to get a ban?
Yeah, take a SS when you join the RDF, and if there's a replacement with one of the players.
The same goes with raids when there are some ninja shenanigans. If your first picture is when the ninja happens, it's pointless. You missed any possible MS changes, and loot rules in general for that raid. People tend to forget to take pic of RL/ML in these cases, but that doesn't really help when you're missing other important screenshots.