If “they” are other players, then you don’t have anything to worry about. Rolling on items that you qualify for is not ninja looting and they have no ability to get you suspended or banned for doing so.
If they wish, they can submit a report, but it is the Game Master’s investigation into your actions that determines if you violates policy, not their report, be it one report or one hundred.
Socially, I would agree. If the group has a particular way they like to handle looting and you are going along with them, then socially speaking, it is usually in good form to adhere to their guidelines. That said, those rules are mostly conditions on grouping with that group and maybe getting invited back. If they select Need/Greed as their looting method and you roll need on things you feel you need, and you qualify for, you aren’t breaking any rules.
The leader may decide to remove you from the group and not ask you back, but we’re not going to penalize you.
The exception would be if you were running a raid as a master looter and you did not adhere to the rules that you established as master looter. That could be considered a scam.