It is.
When the ball is going for the right outlane you can get physical and save it from draining, but on the left side there's like zero chance to save it. I've managed to save it once in about 100 games and I have a very physical playstyle.
It's a shame really that they didn't put a post or something there that would have made the game more forgiving. There's pretty much no skill known to man on how to save a ball from draining on a TWD when the ball has decided to go for the left outlane. I guess we simply have to live with it, but it has taken some time to accept it. Unless you want to get medieval on the playfield (like drilling), but in my opinion that is taking things to far. The game is still very playable - and addictive.