"Reality is incapable of illusion"
This is a follow up on the previous maxim. It simply says that reality can't lie, even though when faced with an illusion, we insist the illusion itself is real, which requires that reality could be somehow deceitful.
But think about this. Reality, to be real, must be real. All of it – no exceptions. Reality can't be anything other than what it actually is. Simply put, an actual unreality is impossible.
Therefore what we take for an illusion is actually a delusion – a misapprehension in our mind – having already decided what something is supposed to be and unwilling to find fault in our impressions.
And reality is of course the only trustworthy context available to us to clear up our delusions.