Why doesn't Robin call the police when she's trapped in Zanic's cottage?

During the 2nd episode of Top of the Lake, Robin follows Wolfgang Zanic from the bar to his cottage. After the little smalltalk interrogation with him goes wrong and Wolfie gets scared, Robin gets trapped in his cottage while he threatens her from the outside with a rifle. But then she doesn't call the police but Johnno and when he arrives he just takes Wolfie's rifle and they leave him there at the cottage.

Why didn't she call the police? Afterall Zanic was still the main suspect and even if his little overreaction was really more motivated by fear than by guilt, Robin still thought him to have something to do with Tui's case, she even called her name hoping she was trapped there somewhere. So did she just change her mind and completely leave him go as suspect (which seems unlikely, especially after what just happened) or why did she just call Johnno and not even look further around his cottage?