Time is relative, such that depending on your frame of reference, things can actually appear to happen in a different order. If events are causally linked though, then cause and effect are preserved in all frames of reference. For example, if you push a button on your flashlight and it turns on, the button push will come before the light turning on everywhere. Nowhere does the light come on before you pushed the button.
There's a difference between saying that causality is preserved and saying that the order in the event is preserved, as you said in the non-causal part. So I suspect there is some equivocation in your argument.
Either way, the order or the causality is governed by physical law, whereas an illusion is not.
"I absorb energy like a sponge everywhere I go. It allows me to see the world and my purpose in it." Zak Bagans, Ghost Adventures (INFJ)
I'm just musing. Iis illusory the opposite of real? Can something be illusory and completely relevant simultaneously, if so does that mean it's real? Are you asking if there is some sort of time particle?