Twice so far, though not in as stark terms, and not recently. Once, I told him to knock it off trying to make a peer engineer who was underperforming look bad in front of the team, and instead to inform our manager of cases where he believed the engineer was underperforming, but not to try to embarrass or humiliate him -- the other engineer was extremely distressed by this engineer. He did stop. Another case he seemed to understand in our 1:1, but ramped up writing long slack comments that read to me as passive-aggressive.
There's a very high risk of things blowing up since there isn't a strong groundwork of trust to begin with, and since things blew up with the previous lead who was too direct with him, so I'm wary to do this without the involvement of my manager.
At first when I joined the team we seemed to have a good amount of trust since I was sympathetic to things that happened in the past to him -- he was treated very unfairly from a director who'd since been fired who let blame travel down directly onto this engineer. The director way over-promised and underestimated and caused the team to face tons of criticism. Most of the burden fell on this engineer; his peers were very little help, and the project was way too large. It was doomed from the start. Everyone on the team flamed each other in year-end reviews. The lead said everyone on the team, including himself, should be fired. It was extremely bad.
Eventually as I disagreed with him and saw he really didn't want /anything/ he'd worked on to change, we started to have conflict. I ended up having a lot more responsibilities added, and decreased the rate at which I held 1:1s with all my peers -- I think he felt insulted, and called off our 1:1s completely.
