This was not a personal attack. This was an attack of their position. A: "We should be doing [stupid thing] X" B: "Good thing you're not the one deciding." B

This was not a personal attack. This was an attack of their position. A: "We should be doing [stupid thing] X" B: "Good thing you're not the one deciding." B is not a personal attack. The entire premise of the point is that it's because of what they said/think, not something personal about that particular individual.