The front of the cabin is not to be left unsupervised. The failure to maintain control of the forward section facilitates a security breach. To quote another report in respect to the limitations of onboard communications;
"A flight attendant who suspects a security breach and is working in the cabin could potentially be half the distance of the aircraft away from notifying the flight crew of the threat”

You report that all FAs were in the rear of the aircraft. That means that the front cabin and flight deck entryway was not under surveillance. This was a serious breach of safety and security protocols. What were these people thinking? In the event of a safety crisis such as smoke or fire, valuable time would be lost waiting for a FA response.