"not entering Russia at a correct port of entry"
I'm laughing at the lack of nuance in laws in general. Some guy crossed the Bering Straight on foot as part of a 27 year quest to walk around the world and the law makes no exception.
I remember as a teen being hauled into a police station because a friend and I had been exploring the storm drains ("sewers") with a home-made flame thrower (okay, so the movie "Alien" had recently come out… Yeah, we left the flamethrower behind in the sewer when we popped our heads out and saw police).
Someone in the neighborhood had called the police because she had seen us going down the manhole opening. (The police said the report came through that some kids had "fallen" into the sewers.)
So I'm sitting in the police station with good cop and bad cop sitting there musing over my case. "How about 'Failure to use a sidewalk when a sidewalk was available'," bad cop said as he read from a book he was paging through. That got a laugh all around…
They let me off after an hour or so of this.
To be completely fair, Russia did decide to make an exception in this case, although it took a couple of months (during which Bushby was detained) to get there.
I am a little bit torn in this case. From our vantage point it's obvious that Bushby wasn't running an elaborate long scam to get into Russia. In the moment... I don't know, former UK special forces guy? Long history of espionage between UK and Russia? Two months seems too long; it's also not as easy as your case of a teenager in the sewer.