Picture the last time I tried to fix a lamp at home and nearly welded the plug to the outlet. That's the level of expertise we're dealing with here. Running extension cords under a wet mat is basically begging for a trip to the burn unit. A business should know better, right? You should absolutely say something before someone gets a free, unwanted espresso and electrocution combo.
Reminds me of my neighbor who tried to power-wash his deck with an extension cord draped in a puddle. Saw the whole thing from my kitchen window. Sometimes you just have to wonder, you know?
That story about the extension cord in the puddle is a classic. The real danger is the water getting inside the cord ends, not just the puddle itself. I've seen a few close calls with outdoor power tools where people forget the connection points are the weak spot. It's one of those things you don't think about until you see the sparks fly.