If there has been a change to the water supply there could be a shortage of calcium causing the yeast to drop out less. If the water supply for the home is surface water and there has been a lot of rain or melted snow flowing into the reservoirs then minerals could be diluted.
Also, if there is a bacterial or wild yeast infection in the beer that is often much more different to clear even with sufficient calcium or fining agents. Hard to rule this out without knowing the sanitation practices or source of yeast.
Calcium level of brewing water is 88 ppm. he is a Type A+++ which carries over to his cleaning regimen. Wyeast American Ale II and US05.
How certain is he of the water composition? made from RO or DI with minerals added back?
Tested water report. Full report
Ca 88
Mg 30
Na 7
Cl 16
SO 29
part of what others were talking about with water source and composition is that unless he collected all the water, took a sample of THAT water for analysis there is no guarantee that the test and the actual water on brew day match up. If your friend get's his water from a surface source, or shallow subsurface source, a lot of rain or melt water would change the composition significantly, if, for instance, he took a sample mid summer and there hadn't been rain for 5 months and then it rained for a week right before he could have brewed with near distilled water rather than 88 ppm calcium.
You could save a sample somewhere warm for a couple weeks and see if any funk develops that would rule out wild yeast or other contaminant pretty well.