There is a world somewhere between reality and fiction. Although ignored by many, it is very real and so are those living in it. This forum is about the natural world. Here, wild animals will be heard and respected. The forum offers a glimpse into an unknown world as well as a room with a view on the present and the future. Anyone able to speak on behalf of those living in the emerald forest and the deep blue sea is invited to join.
It certainly is fully confirmed that a large male brown bear was killed by a tiger!!!
You do a formidable job of gathering information and who knows, maybe we'll have a new big male brown bear killed by the same tiger, and years may go by and no sign of predation on another big bear is found. If there really is an advantage of tigers over large adult male brown bears we would hardly (historically) have so few elements and factual narratives. There is no prevalence of assumptions about whether bears win or lose a fight, as losing a fight is not synonymous with the explicit determinism that large male brown bears are likely to succumb in an eventual battle to a tiger.
Killing by a lesser tiger (Odyr) has not been proven, it is still an assumption based on the issue of territorial dominance/control. All evidence incriminates him, but there is doubt about materiality. Even so, we will never know the circumstances of the combat, nor the physical and health conditions of the defeated bear. As a hypercarnivore, the tiger is always on the lookout for predation and circumstantially visualized that it was facing an opportunity (but what would this advantage be?). As tiger predation on large male brown bears is not common, there will always be speculation as to why the tiger easily beats this opponent (easily due to the absence of signs of post-fight injury). Possibly here lies that something unusual caused this tiger to do so well in front of this bear.
About black bears, the material posted here consolidates that their predation by siberian tigers is fully documented and reported, including large male specimens of this species.