Oh, I missed that comment---I thought the top comment was same at that time, but it has changed since then. That suffices as "explicit alternative explanations". Thank you for pointing it out.

I still believe that the presumption of innocence should not apply in this case, because fingerprinting is already close to guilty (if you don't agree to this premise there is no point for further discussion, so please refrain from arguing against this specific point). You are right that feature detection is not fingerprinting but they are virtually indistinguishable; given how widespread fingerprinting has been, it was enough to suspect so.