I get a call, 630 in the morning on a Saturday and it's from work. "Say, do you know where the screws for the screen are?"
"Yeah. They're on the dishrack."
"Oh right, thanks. Oh man, if I would have pulled a shot without the shower screen and screw in place, those grinds would have been all up in there, costing hundreds of dollars of damage.....(you're an idiot; why didn't you reassemble the shower screen when you closed?!)"
"Okay, well have a good morning. See ya."

And it had me thnking, "Does it really?" We use the beautiful Cyncra Synesso and I backflush every few days. I think that even if that were to happen (one, you should notice right away that your shot came out funny as there is a significant difference), you could always clean up after yourself. The machine is nearly idiot proof.

So who's right?