I'm typing this 3 miles from KSNA, my "home base" as a private pilot. To cut through speculation about 20L being difficult to tell apart from Taxiway C, the runway has several cues:
Big "20" and "L" .
Chevrons pointing to the threshold.
White edge and centerline on 20L, yellow on Charlie per international standards.
REIL (pair of strobes, "Runway End Identifier Lights", guess they didn't serve their purpose).
VASIs on the right-hand side of the runway (side farthest away from C)
IFR hold bars on both sides of the runway at intersecting taxiways.
20L is not a precision IFR runway, hence markings are VFR and better than most airports. As far as brown grass, it's very green right now due to our epic rainfall.
I hope it all works out for him...with the other errors and detached demeanor, perhaps a medical issue?