I think it is laziness to do proper research unless they are consulting cheap experts. Not sure Yasmeen would be arrested at that point, surely she would have been asked to go to the police station for questioning and only arrested if she refused to go. The state she was in she would have agreed to anything.
Anyway it should all be over and done with tomorrow when they find Geoff's spy camera. This should show him threatening her with the bread knife. I am not sure if there is audio but even if there is not, when Yameen gets over her state of shock and tells the police that he threatened to kill her, she can claim self defense and the video should support this. As I understand it you do not have to wait until an attacker starts to harm you before you fight back, if you believe your life is in danger, after a verbal threat you are entitled to take appropriate action. Of course we know this will not be cleared up tomorrow, I fear it will continue for a while yet. .