It's obviously what happened, he got a dodgy result cooked up which is why he was apparently galavanting all over the place when he was 'positive' cos he was never positive but couldn't say that now as he's too deep in the lie!
There definitely should be some severe sanctions of some sort.
Not uncommon especially for female tennis players to retire early. Most come back though. Hell even Kim Clijsters came back last year.
Wimbledon bans Russian and Belarusian players.