Now I'm lost, because that's exactly what I said.

"($1 == $null) and ($1) are the same (equally false) when $1 is 0 or $false"
//tokenize 32 0 | if ($1 == $null) { this condition is false }
//tokenize 32 $false | if ($1 == $null) { this condition is false }
//tokenize 32 0 | if ($1) { this condition is false }
//tokenize 32 $false | if ($1) { this condition is false }
All equally false (not the method, but rather the result and the conditions ($1 being 0 or $false)). Maybe that's clear now.