I think it may be wise for your to do two things:
1) write down in as much detail as you can remember the camera situation as you described in your post including times and dates if you can remember them plus also include events that happened after the camera was returned (the purpose of this is to provide a record that you can refer to if things escalate and then you are less likely to forget some points if you are discussing with police, etc.) and
2) discuss what options you may have with the police. Even if nothing happens at that point, the information is on file and it may be beneficial if things escalate.
Also, I don't think they can charge you with theft because they lent the camera equpment to you to begin with (it's not like you broke into their house and snatched the stuff) and you handed the camera equipment back to them.