I did a lot more than play 'monday morning quarterback' and quote anectdotal information when you asked for help, Bob.
There's a lesson to be learned here and it's not about mg/kg or about one's drug of choice.
The point I'm trying to make is this (and I learned it from my vet): If you kill the bacteria in a koi with a massive internal infection all at once you risk kissing your koi goodbye from organ overload if the damaged organs cannot process all the waste. And a lot of folks don't know that.
This lesson applies to more than your fish, Bob, and this lesson applies to other drugs besides Baytril.
In your case, unfortunately, this lesson would appear to have gone in one ear and out the other 'cause you're too busy defending your actions. Good luck,