Disagree. If I happen to pick up the pace when some rando(who originally was running at a slower pace) tucks in behind me and stalks me on my run, I'm not issuing and inviting a challenge....I'm giving the hint that I don't welcome your presence and wish for you to leave me alone instead of stalk me without saying anything, weirdo. If you wanted to "get a workout in" then you can do that elsewhere without hopping on my back. Clearly you're not following a strict training schedule of you haphazardly decide decide to pick up the pace when someone passes you to get in "some tempo work."
Then again, personally, I'd probably just let him pass or say something. But I assure you most of the time I'm not issuing a playful challenge, I'm trying to avoid your unwanted infringement on my otherwise enjoyable run.
This. Mr. Anderson is probably the guy who assumes that a girl is just "playing hard to get" and keeps chatting her up and trying to make plans for later while she's doing everything she can to politely hint that she's not interested. "Oh, she's just challenging me to be more aggressive when she tells me that she's hanging out with her friends tonight. Well I'm buying her that drink even if she says she doesn't want it! That must be what she really wants."