I hate to be that guy, but all reports I've seen suggest that the bomber crashed near Mozdok, which is like 700 km away from Ukraine's southern border. It's of course possible that the aircraft was struck by Ukraine's air defences and the pilots tried to limp home for whatever reason instead of making an emergency landing on the nearest Russian airfield; and indeed that's what the Ukrainians say has happened. Still, I wouldn't count out the possibility of it being friendly fire or something else.