Searching by specific killer, apparently only shows deaths by scrolls of immolation for non-unique monsters

[Predelnik]

Not sure what's causing this but here's an example:
https://dcss-stats.com/search?filter=Killer_is_Death+yak_and&filter=Version_is_0.34
Shows just 20 deaths and all described as killed by an exploding death yak... ignited by their inner flame
However for Sigmund it seems to correctly show 17k deaths:
https://dcss-stats.com/search?filter=Killer_is_Sigmund_and&filter=Version_is_0.34