Week one is always a crap shoot. Teams going up against a new QB, coach or coordinator are at a huge disadvantage. See us, AZ and the Rams last week. It becomes completely unpredictable when you don't have the ability to game plan effectively.
That said I did see some of the game and Palmer looked like he was hearing footsteps every time he dropped back. I didn't see the early part of the game so I don't know how good the NE pass rush was. So I don't know if they got into Palmers head or if he is just not playing with confidence right now but if he doesn't get his mojo back the Cards won't be doing anything significant this year.
You should probably also wonder if this was a huge trap game for AZ. Believing they are one of the most talented teams in the league and expecting a shell of the NE Patriots team very well could have had them looking past the game.
I was wondering about was the officiating though. AZ seems to have a philosophy on broken plays of trying to draw the deep PI. Palmer will chuck it over the head of his deepest receiver instead of throwing it out of bounds. Then the receiver and Arians from the sideline start screaming rape and somehow the flags come out even with blatantly uncatchable balls. I'm wondering if the officiating is catching on to this ploy. I believe AZ did lead the league in PI calls last year helping them in multiple close games.
This week should tell us much more about how good or bad many teams are since there is now tape on every team so game planning is in full effect.
Essentially I don't think you can put much weight in last weeks performance for AZ. That is not to say TB doesn't look very good. Beating a division rival in their house is always difficult and Atlanta always seems to be able to play their division foes much better than everyone else. Kind of like the Rams.
I'd still have to give the cards the advantage but if they do come out and play again like they did last week then we can probably draw some conclusions about how good or bad they may be this year.