Harry asked for a room to train and practice DADA. (Although what Neville asked for in the movie is unclear.)
Malfoy asked for a room where he wouldn’t be disturbed.
That’s true. Plus, Harry didn’t know what Malfoy was using it for, so he didn’t know what to focus on to get it to open up. At least that is what I am going to go with. ;-)
I did really like the DA scenes. And I don’t think I could love Neville more. I loved when he yelled at Bellatrix, “Better, now that they’re about to be avenged!” I’m really, really hoping that we see much more Neville Deathly Hallows. He’s my favorite character.
But Trelawney got in.