No, actually, he's got that part right. The match is against $_, so no =~ needed. He's assigning the groups in the regex to those variables (not trying to match what's in them). I'm pretty sure that was the goal.

local $_ = "0A72656B636148206C72655020726568746F6E41207473754A";
while(s/..$//) { print chr(hex($&)) }
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