Bottom line here is the HPFP is lubricated by the fuel. Starve it and then it has no lubrication.
Run water through it and then you will have the same results.
If I were you I would want to pull the top filter and shine a light into the fuel bowl. If it is clean then go down and drain the lower one. If it flows good and you see no water then I would be ok with it.
So that appears to be the rest of the story. He is judging fleet vehicles accross the board.
08F250 CC 6.4 PSD
Banks 6 gun/ram air
40' Stoneridge 5th wheel, coming in at 15.4K.