Thanks for sharing your experience with us. Nice to know R5 is so well sealed.Since this thread is about the R5 teardown, I'll mention what recently happened to my R5:
I got my new R5 and lenses a while back (yay!). So I decided to put it on a tripod with a RF 70-200 f2.8 lens with lens hood and put it out on my outside deck at minimum focus distance for 200mm at my hummingbird feeder. I started an unlimited 8K raw video with a formatted 325GB Prograde Cobalt card. My goal is to extract, from the video, some nice 8K pixel wide still frames of hummingbirds in flight or in a good pose while sitting there (in pre-determined focus). Since this is about the fourth time I've done this, I thought I'd go back inside and get on the computer and come back after the CFExpress card filled up.
After getting distracted for about an hour while focused on my computer, I looked outside and marveled at just how hard the rain had been coming straight down for the last 5 minutes or so. Then it hit me - BAM - wasn't my camera outside on the porch? DOHHHHHH!!!!!!
I ran to my deck, grabbed the camera & tripod (still in the pouring rain) and brought it inside. I got some nice quality towels (the kind they use at car washes) to slowly dab the water off the camera & lens. When I got most of it off I dared to look inside the lens hood to see how much water got on the front lens - and saw there wasn't a drop on it! - There wasn't any moisture at all on it! Wow - that long lens hood really made a difference, way more than I'd expect. After getting all the water off it (including the back LCD) that I could see I left it in a dry location to sit for a few hours. After that I opened the battery door (remembering seeing Sony Alpha videos of water running out of its battery compartment when people did an intentional water test with it). There was no water there - not a speck of moisture. The top LCD had no moisture anywhere (including under the glass itself which I really worried about). The back LCD & EVF had no moisture on them or under the glass. Next I slowly took the lens off and saw that there was not a speck of water around the mount surfaces, at the back of the lens or inside the camera that I could see. Looking through the lens, there was no water or moisture at all that I could see. I couldn't find any moisture anywhere.
In the few days past, I have used the same R5 and lens for lots more pictures, and there was no problem whatsoever.
All I can say is "Thanks, Canon! You did a great water sealing job!", followed by "I hope I'm never this stupid again!"