I sometimes wonder if Turbine staff trained with an ISP as the stock answer of it's not our problem seems common.
It is partly your problem in that you seem to send an inordinate amount of data from the server to the client and in a asynchronous apparently unacked fashion that contributes to the problem as the loss of a packet or two, 4% packet loss when I was having my issue , shouldn't cause the client to lock. Rather the client should just do a refresh.
Given Aussies are usually always playing non peak blaming it on peak traffic is a bit over the top.