He tried to slip poison to a bad general and somehow ended up drinking it himself.
Putin hissed “Гранула с ядом во флагоне с драконом; сосуд с пестиком имеет напиток, который является истинным” and then keeled over.
He won’t live through the night but has a at least one clone standing by.
The clone has cancer, and has gained weight.
That's how you can tell.