Blocking formation?

IN this game: #2396913, my opponent got a lead and blocked the ball in a corner. I don't see any way to get out of this formation, it seems that it needs to be banned.

Is there a way to break it?

I remember earlier the rules mentioned a prohibition against blocking the ball in, but that it wasn't implemented here. I feel that, if that won't change, the rule can still be enforced by manually flipping the outcome against any player that does it.

This sort of position has come up before. The problem is that the blockade is only considered illegal if none of your pieces is in there. So, if you move your player off the field then they'll have to undo the blockade.

Hope this helps.