Chalk it up to an adverb gone wild. Originally used for emphasis in questions, it's now used emphatically everywhere. When he did that... = At least the first time he did that. Whenever he did that... = every time he did that.
when·ev·er
adverb
… 1. used for emphasis instead of “when” in questions, typically expressing surprise or confusion.
"whenever shall we get there?"
I blame Shakira's -
Whenever, Wherever - for popularizing the word leading to excessive applications in pop culture. Maybe you had to be here.
Whatever.