Well, it was very embarrassing to take a victory lap with the war getting bogged down, and revealed motivations for the war that contradicted Putin’s statements

Well, it was very embarrassing to take a victory lap with the war getting bogged down, and revealed motivations for the war that contradicted Putin’s statements, and aligned with the “blitzkrieg” analysis of Russia’s early failures. So, true, it’s not proof, but Occam’s Razor comes into play here.