I dont think even in Chalav Yisroel does a jew milk the cow, Its probably the same machine in the same dairy farm (Likely a special run where someone just watches the process)
It costs too much to change over from non-CY to CY and CY is made daily. Instead usually the entire farm is CY.
Basicly the difference is that for CY milk, the mashgiach inspects and seals the tankers.