At the end of the day you have to ask yourself- If you see an incident out of an aircraft window as a passenger, how far can your protest go if you believe that the safety of the flight is in question?
You must have the right to refuse to fly and be returned to the gate if you honestly believe your life may be put at risk.
Cabin crew CRM must cover this area. Cabin crew should made aware that any reported defect seen on the outside of the aircraft should be immediately reported to the flight deck. It should also be recorded in the cabin crew flight report.