I think that was just being defensiveness when he knew he made a wrong decision but couldn't do anything about it anymore and had no argument to defend himself. Anyways whether or not it was intentional, he produced a situation that no matter the outcome of Mercs protest, this years title is severely tainted.You're right that the correct decision was to end the race behind the safety car, BUT if he wanted to make it about what happens on the track I don't think Merc would fight like they're going to fight this decision, if he red flagged with a few laps to go and everyone got tires and said "let's do it on the track"
I genuinely don't think Merc would have a beef with the red flag because honestly Lewis would've won that too. He made the only decisions (plural/multiple choices) that could've resulted in Lewis losing the championship. It wasn't just one thing he skipped past. He ignored two different rules to allow Max to get right behind Lewis on fresh tires and when called out by it he just threw out "It's about motorsport" to Toto. At that point it's not incompetence or panicking to me. That was a purposely made decision.