@trent15 Yes this is the normal behaviour. Your are obliged to choose casualtites as careful and reasonable as possible. Choose them for your opponent the same reasonable way as you would choose them for yourself.
In case of doubt ask your opponent before you continue a game.
Also, in some cases you would want to ask your opponent for his OOL (Order of loss) before you roll any dice.
In case you would incorrectly or irrationally choose your opponent has the right to object. Most of the times this results in a reroll.
This has been working pretty fine for years.