I manage the FOH for an independent living facility (old people). We have to batch cook a lot of proteins because of very tight and chaotic meal periods. Everything gets baked for 15-20 minutes at 325°, with an inch of water in the pan. A whole sheet tray of redfish getting baked half-submerged.

When I tell her they are complaining that it's dry, she says that's impossible because, look, it is wet. I want to explain that what the old folks mean by "dry" is actually because everything is tough and overcooked.

How do I explain what is happening with the food, to the extent that water does not equal tender?

ETA: I'd like to explain the actual physics of it, not just argue with her.