I think it's pretty innovative, especially since I'll bet they ended up with a lot more bang for their buck with the uplighting aspect of the installation. I probably wouldn't have thought to do it this way.
I would like to hope that the EMT spacer has a sheet metal screw going through it. I have done this before when I needed to space a panel slightly further out from a wall and didn't have enough washers. I don't see the harm in it and if there is, nobody knows.
No doubt that those fixture lenses are heavily-gasketed. I have worked with a ton of those in the past. I would almost think that they are more water-resistant when installed upside-down. The lens is molded and directs water (as if any would even get in that canopy anyway) down and around the edge when upside-down. Water would have to go down, then back up and around the gasketing to get into the base. Now, I might have drilled a few weep holes in the base section just in case.
Water is going to end up in them somehow, kind of the same way insects end up in perfectly-sealed fixtures. A phenomenon that we may never be able to explain.