He would never leave willingly if there was an existing extradition request for him. So they waited until he was out, however that came about. he was guaranteed

He would never leave willingly if there was an existing extradition request for him. So they waited until he was out, however that came about. he was guaranteed to be arrested on exiting if only for the bail breach. At which point he is in custody and you can serve the extradition request. Similarly the US will not request extradition for some suspects and wait until they set foot in the US and arrest them then. Saving the need for an extradition battle. If they really want you and you are Russian, they wait until you go on holiday outside russian borders and grab you as you step off the plane.