In case you're talking about "I know you're not being literal here":
Because only a lunatic would think that high-status people think they're literally no longer classified as Homo Sapiens?
In case you're talking about "Apologies if I'm misinterpreting you here":
The word "if" is generally used to indicate conditioning on an event: i.e. "considering only the situation in which this is true". Nothing about the word indicates "certainty" about anything.
Lunatic? Well, I avoid making statements about my own sanity. But people sometimes decide that they are superhuman, or that others are subhuman. The ancient Greeks called it hubris. Nowadays we are more likely to say someone is out of touch, or living in a bubble. It shows up in comments like "Only the little people pay taxes".
Because only a lunatic would think that high-status people think they're literally no longer classified as Homo Sapiens?
In case you're talking about "Apologies if I'm misinterpreting you here":
The word "if" is generally used to indicate conditioning on an event: i.e. "considering only the situation in which this is true". Nothing about the word indicates "certainty" about anything.