Realistically Putin was never going to let him leave. Navalny was doomed from the beginning. He was too big a threat, even on the other side of the world. If he ever escaped Russia, Putin would have sent agents out to 'Trotsky' him.
If you're talking about the assassin that was just sent back, he wasn't from the team who had tried to kill Navalny. Wasn't even from the same Russian intelligence agency, and those guys -- especially after being identified -- are, I imagine, never going to be leaving Russia again. Those guys were GRU. This guy was FSB.
The guy who just got sent back shot a guy in the head in a park in Germany. And while he still managed to get himself caught, he actually killed his target, and unlike the GRU guys who tried to hit Navalny, managed to refrain from performing a recorded confession to his victim, and unlike the GRU guys at Salisbury, managed to avoid killing random civilians and hurting a police officer and starting an international incident over Russia running an illicit chemical weapons program in violation of treaty obligations. Frankly, if I were Putin and set on having someone assassinated, I think I'd lean towards having the FSB assassinate people and focus on keeping the GRU well away from assassinations and preferably any sharp objects or heavy machinery.
Yeah sorry, with his I was referring to Putin as in "we sent him a tool to effectively murder unwanted persons abroad". Now, that I read my text again, I do understand that I chose poor phrasing.
The five policemen with submachine guns made him lie down on the ground and surrender, but only after he had assessed the situation with an ice-cold, calculating look, as one policeman, still impressed, told the court.
The witnesses who witnessed the murder of Selimchan Changoschwili, a Georgian of Chechen origin, in the Kleiner Tiergarten also spoke of a cold-blooded perpetrator. The way he approached the man, who was already lying on the ground, and shot him again in the head with his right hand outstretched was an execution. He had approached his victim from behind on a bicycle, from which he had fired two shots.