Most tiger kill lion accounts often in the end turn out to be a lioness, a young lion, a sick lion, an old lion, an unusually small weak lion, or some other advantage like a chain around the tigers neck, or trainer stabbing lion giving the tiger an advantage during the fight.
For instance, the Darwin account that we all know to well, a lion gets its stomach ripped open, yet the manes saves its throat and neck.
It turns out this lion Darwin was talking about was way past its prime, very old, with bad teeth, most likely broken and gone. The tiger was in the prime of its life and powerful.
For years we didn't know this, but now we do. Yet still, this old lion with bad teeth, its mane still protected its neck completely. It would now make further sense, the other account where the lion dies very quickly that Beatty mentioned, very well likely was not a full grown full maned lion.
Edmonds Menagerie account below is the same account cited by Darwin in his book.
Large aggressive Bengal tiger kills old lion way past his prime. The lion had teeth that were in very poor condition.
So its obvious this fight was not fair at all.
A few years later I was surprised to see in the newspapers that the head-keeper Scott had been killed by a large grizzly bear which had escaped from its den. ... Mrs. Edmonds during her peregrinations frequently visited the North with her menagerie, which always contained some rare ... it from a fine South American jaguar, which it had attacked and killed by ripping up its abdomen with its claws. The same tiger some years before had killed a full-grown lion in a similar manner.
Here is the proof below that this lion was in poor condition not able to defend itself.
... lion, and killed the latter in a few minutes, but the duel was not a fair one, for the tiger was a fine lusty male in the prime of life, whereas the lion was a patriarch whose best days had passed and whose teeth were in anything but fighting order ...
further insight and investigation, it also appears that Darwin in his
book the decent of man, also cited the same account. With the same exact
description, taking place in the same country England, at the same time
and year. Several years ago from 1860 is exactly 1857, to which Mrs
Edmond stated the fight happened. Edmond's menagerie was in England,
and it was a
traveling menagerie, covering various towns and cities. Bromwich is in England.
1857 a tiger at Bromwich broke into the cage of a lion and a fearful
scene ensued: ‘the lions mane saved his head and neck from being much
injured, but the tiger at last succeeded in ripping up his belly, and in
a few minutes he was dead. -The Descent of Man, and Selection in
Relation to Sex. Charles Darwin”
states that the mane dose work, and even sites naturalist saying a
young lion will not fight an older full maned lion, he states the fights
are vicious. But with this new information, we now can assess, this
lion Darwin is citing is most likely the same old lion from the Edmond's
account. Which again, is not a fair fight, it had bad teeth, and was
very old. Yet its mane protection worked.