The only time I've ever seen a bike that had a brake that had gotten that hot, it was one of the first Kawasaki Concours 1400 sold in Colorado. After it cooled, he took the caliper and secured it so that it couldn't fall into the wheel and rode it slowly back to Denver. It took a couple of weeks for a new disc and caliper. I didn't see it when it was hot, but after it had cooled -- the disc was badly warped.
In '98, when I had my ''99 Concours, I had friends who bought a brand new Road King and loaded it with all the Screaming Eagle Stage 3 equipment you could get. It was delivered to Thunder Mountain HD on Wednesday and they were going to pick it up on Friday afternoon. But Thunder Mountain called on Friday morning and told Larry that another equipped just like the first one would be there on the next Friday. The day after it had been delivered, the factory had called and told the dealer to get the first one into a crate immediately. He never got any explanation. He'd had # 2 when I pulled into the gas station we both used. After I looked at it for a minute, he got on, started it up and gas started pumping from somewhere onto the hot exhaust. He asked me to bring his wife to their house, got on and rode swiftly towards their home. I was still pumping gas when he got there, but the fire had blown out as soon as he started moving. He took it back to the dealer and and Harley replaced the engine. They finally got home, running well and assumed all was well. But, no. They rode out into the country and the bike started slowing down. Turns out that the brake fluid was heating up and squeezing the disk until the bike stopped. They waited until it cooled down and started for the dealer. They had had to stop 3 times before it could move again. They were about 2 miles from the dealer when I slowed to a stop. He couldn't get across the traffic to the shoulder. He had made it to a long light and when it changed, he was able to get the bike moving slowly. He came to another light and by then the brake was barely letting the bike move. Another light change and a woman behind him in a big Buick, nailed them and did a lot damage to the bike, but none to them. The bike was in the shop for another 2-3 weeks, but as I remember, I don't think he had any more trouble. He was a guy who wanted the best and frequently informed everyone he know that his Harley was a great bike of exceptional quality. I think he'd paid about $43K for it. I had paid $7500 for my Connie and I used to razz Larry by telling him for the money he's spent on his HD, he could have bought 5 Concours. Since nothing ever went wrong with the Concours, he could count on being able to ride one of them any time he wanted to go anywhere because one of them was sure to have a full tank of gas.