The guy wasn't stupid. He knew going against Putin meant death if he failed. At some point during his attempted coup, he realised it wasn't going to work and was faced with a choice: die now, or "back down" to scheme his way out of an almost certain death later. Turns out he couldn't. ¯⁠\⁠_⁠༼⁠ ⁠•́⁠ ͜⁠ʖ⁠ ⁠•̀⁠ ⁠༽⁠_⁠/⁠¯ Oh well, nothing of value was lost.