It's bait. 100%. It's just too ridiculous otherwise.
But also notice at the end of the chapter the shoe of the person standing next to Miki's supposed 'corpse'. It's a fucking military boot.
So... couple of things here: The Author likes to do unusual plot points and doesn't play things straight.
Mostly, if something has been done before - then the Author won't retread old ground. I think that's the same sort of thing going on here. I'm interested if the SFX used was also misleading but I don't translate so free shruggies. Point is in the lead up to that page we get a few things.
A) Miki looks shocked. She looked like she had accepted it but then panics. But why?
B) Military Boot at the end
C) The blood from the 'bite' looks an awful lot like blood splatter from a gun
So what likely happened was: Military showed up and Miki was like "oh fuck" and they shot her zombified friend.
What they plan to do with Miki is anyone's guess. Probably hold her ransom to force the others to come out of hiding.