Another bad choice on the writers' part: how did the terrorists find out about the key card so quickly - did Dwayne just call them on his cell phone?
Getting Rudy's card was the plan all along, apparently.
One would suspect that the terrorists, wanting to be able to infiltrate CTU, would investigate the employees looking for a weak link.
Once that link is found, it's easy enough to expolit a couple of druggies looking for a big payday.
That said, how Rudy got into the building is a mystery and sloppy writing.
Also, a secure building should log people in and out. A second attempt to enter a building using a card with someone already logged in should raise a flag.
This show is compelling and all, but the writing is increasingly lazy.
SD