Near the end when Angela and Pablo are listening to the recorder in the penthouse, Angela is obviously rewinding the tape. However, the second time when she rewinds the tape, the audio implies that it was fast-forwarded, as the recording is a diary describing events in chronological order. Watch the tape reel when she rewinds the tape. As it plays forward the reel turns more times than it was rewound. It is impossible for her to hear very much different dialogue without rewinding the tape much more than she does, and then it wouldn't make sense as the dialogue is chronological. In reality, she would be hearing the same spoken passage repeatedly.
(at around 24 mins) The old man at the start says that their mobile phones, TV, etc. don't work but when Pablo and Angela go up to the third floor to get the keys (at around 1h) the TV is obviously on and working.