What should I do about dishonest NCOs?

Last week I was having a conversation with an NCO (SGT) and during that conversation he was trash talking my NCOIC, First Line, and input how thing need to be ran and we need to be reminded that we work for our NCOICs and he lets us do to much and doesn’t make us work for him. He was referencing the fact that currently four soldiers, myself included, are working on going to selection (CID, SF, CA, or CI).

I notified my first line about this conversation and how it was unprofessional. My first line agreed and said he’d handle it.

Today I got an ass chewing from that NCO for “lying” about things he said and was warned to keep his name out of my mouth or else he’d make my life difficult and would take further action. My first line was present and after the fact just told me to continue to do what I need for my career.

I don’t care about he ass chewing but I do care that I was called a liar when I’m not. Is there anything else I can do or is it not worth my time?