The video footage was released as part of a subject access request, not for any reasons related to any kind of trial. Any omissions in the data that was asked for should have been noted and explained as to why they weren't providing the information.
Zayna doesn't have a "defence team" because she isn't facing any charges in relation to this incident.
The at least 40 hours in custody is the time covered by the CCTV footage and the logs during which time Zayna was detained at the police station. It doesn't include any time spent at hospital. No explanation, justification or authorisation was given for detaining her for that long.
Honestly, people commenting need to at least read the Sky News article that is linked in the OP to avoid asking questions that are specifically covered in the article and the linked video.