Remember in the opening scene of Ada's game..(of course you do...she's naked..)
She had a falsh back of when she first talked to Simmons (Carla) telling him that she wasn't interested in his game..then it falshed back to the present time. When did that flash back take place?? Before the RE6 game started?
it was a trap of some sorts. i believe she was in that place because of a job that turned out to be false or just a cover up from carla.she was being chased by carla's guards, i'm guessing they were not infected. she stopped caring because she believed she had found a place to hide, it's possible she was out of ammo and especially since she didn't have her bowgun with her, but actually, she had been led to the room where carla had left the phone. carla knows ada, and she was sure ada would be curious. carla then called (i'm pretty sure she could be watching ada from cameras hidden in the room)the scene happened, and ada chased off after carla.
it was a set up from carla to get ada to come and meet her.
i didn't think it was an out of place scene, to be honest, and it wasn't that difficult to at least get a notion of what was happening. this is one of the scenes most people like to whine about and say the game was poorly made (not talking about you, agentada, or you, TC), but seriously, not a bad scene. i liked seeing a more vulnurable ada. ada's talents are in hiding, staying in the shadows, watching and then hunting--for info or for a virus. when you take that away, and put her in a situations where she's being chased and out of her 'habitat', it makes her more human. she's not a mary-sue. she was being chased, had to hide and was led into a 'trap'.