I'd really love to give them the benefit of the doubt, but they're apparently not storing your deck status in an easily-countable array. Add the password thing and the animations problems, and we're dealing with this guy:
The thing that gets me is that it's not even a matter of them needing to have made some "number of cards in deck" variable that they aren't updating or whatever. It's that for the game to work correctly, they need to keep track of the cards in your deck (duh), and the cards in your deck that haven't been drawn yet. That you can't get the count of cards from that is what's confusing to me.
I've heard the speculation that they are trying to keep track of deck card count client side so that the server doesn't need to send the size of the deck every turn. I'm sure there is some technical reason that they haven't abandoned this idea, but I don't think that's ever going to work perfectly. Even if they get it mostly right, there will be some edge cases that mess it up. And I don't understand why the number of cards remaining in your deck isn't considered essential enough to warrant sending data from the server to the client. but again, that's speculation.
I don't think Making Fun is a bunch of stupid people and that its fair to characterize them as idiots, but I do think the team isn't really aware of how important the size of the deck is to gameplay.
I haven't had time to play the beta with a pad and paper but I'll record deck counts through the game when I do.