Please don't worry.
You are not liable. You didn't do anything to cause this and you took every step that you could to stop it.
Nobody ID you anyway.
Well, whether you did or not you cannot do more than make a report.
Nobody who is exercising care falls on broken eggs anyway.
Please don't worry. This just isn't going to lead to action.
Well, they can be but not here.
No, you would not be liable for the reasons above.
all the best.