One more post, on one broken leg.

[Eva Elisabeth]

Since I brought up the stirrup question:
I think, if Booth had mounted from the right side, for me it would have been almost a proof for a broken leg, but not v.v. (Mounting from the left for me still wouldn't prove it.)

Joe, I can tell you my experiences. First I didn't want to post this, could sound braggy, and that is absolutely not my intention.

I second to 100% adrenaline does a lot. When I was younger, I danced a lot on stage (ballett), and it happens quite often that you have blisters or even bleeding toes that really cause pain under normal conditions, but on stage you feel nothing of that anymore. Or you dance with other injuries because it's your job and you are also somewhat addicted to it, especially to that adrenaline rush. I've never taken any drugs (don't even drink alcohol), but I assume this is something similar. Once I broke my heel during a performance after landing a jump badly, it DID ache, but I could finish and stand it - until I was at home. Then, when resting, pain increased terribly, and suddenly I wasn't anymore able to go even two steps.
You can ask any dancer, especially the female ones. It also happens they break a rib if the partner grabs them too tight when lifting, and they go on performing. Once you are in full flow and hear the music, it's like flipping the switch. (Not always, but in the very most cases.)

From these experiences I could well imagine Booth was indeed well able to ignore a broken leg for a certain time.

And - an adrenaline peak doesn't - can't - last endlessly, that would cause death sooner or later. Anyway, these "functions" of adrenaline (to suppress pain, to rise the blood pressure, to increase respiration,...), as you may know, are a relict of the Stone Age (as our entire body is still adapted to those former environmental conditions) to deal with "fight-or-flight" situations. Evolution takes time. When the mammoth or the sabertooth injured Fred Flintstone and was still after him, it was important Fred was able to run and flee to a safe place before he could take time to suffer and care.

We've just mentioned adrenaline, but endorphins have a similar share in this system, too.

On the whole, to me, this chain of events and developments - JWB broke his leg on stage, invented the horse fall to let his performance appear a perfect one, and, due to increasing despair and depressing circumstances, confessed the truth in his diary - makes sense.