I also say right at fifty-fifty. Both sides were at grevious fault, and both sides took actions, both accidental and intentional, that further worsened the situaton.
Regardless of how the original fire started, there was NO firefighting equipment on hand when the final assault was made. Even though it was known that Koresh had threatened to torch the place and was suspected of distributing stores of fuel. It took something like an hour to get the first firetrucks on the scene, and even then they weren’t allowed through police lines for some period afterward.
The ATF knew that Koresh was leading his followers with visions of “the apocalypse” which he characterized as being assaulted by government agents. One might think that the officials might want to play down the obvious “self fulfilling prophecy” part of that.
There’s considerably more- on both sides of the coin. The infamous “flame throwing tank” image was in fact a military demolition vehicle, and the “flame” was a piece of wallboard/gypsum that fell across the front. In a static phot, it looks plausible as flame, but to see the series in a video, it’s obvious it’s falling debris.
On the other hand we were told that ATF/FBI agents under no circumstances used anything that could have possibly caused the fire- no tracer ammo, no pyrotechnic grenades, no flashbangs. Except that the spent hulls of two “flashbang” grenades were found in the rubble- these use magnesium powders to make a bright flash and noise to disorient the bad guys.
We were also told that Koresh and his followers were illegally converting semiauto rifles into “machine guns”, except that, even though dozens of burned weapons were found, none were shown to have been converted.
The infamous missing door, the supposedly malfunctioning video cameras, Koresh’s idiot bible-quotes, the claims the FBI’s IR camera was unique and had been dismantled, the list is endless.
But ultimately both sides lied, both sides screwed up, both sides share the blame.