It sounds like you think Putin is a nut job. I am confident you are wrong. He just made a mistake. It was not his first one.
Keep your imagination to yourself, and do try to own your own opinions instead of speaking in the neutral tense to dispense insults. What you call a mistake has actually led, directly, to a destabilization of conditions between Turkey and Russia whereby Russia can claim wounded and betrayed status not only with Turkey, but also the Obama administration and NATO. Putin can exploit that new status to support all sorts of military adventures, and will. If you don't think he'd sacrifice a pilot for that, you're a child.