Usually, the empty health bar means the enemy player got 1-2% hp left, but yea it's awful to see something like that. Either show the actual hp or remove the empty health bar.
An easy way to avoid the appearance of a character having no health (visually empty bar) when they are hanging on by a thread of as little as 1 health point would be to add an additional visual identifier such as a pulsing red frame around the health bar to signify a character on deaths door with the smallest fraction of health left even if the bar can’t visually show that small fraction inside the bar itself.
