Part of that could more be due to Edea taking control of Galbadia at that point. She was cocky and probably didn't think she needed the incompetent Galbadian military (which she didn't.) If it was intentional, she could have been setting things up to be easier for the party just to lure them out and to capture these SeeD that she hates so much.

Then again, it could just go back to Galbadian military simply being incompetent. Selphie in the others got into the missile base no problem, and the only thing that raised suspicion was a salute after they had already done a lot to sabotage the base. Zell and the others easily tricked Galbadian military in the D-District prison to escape.