C. orientalis should have pale spots in the paravertebral zone, diagnostic for this species and albeit an out of focus image, not visible to me here. Unless you can confirm the spots were observed it otherwise looks like robustus. Up in the air for the time being pending any comments you feel you can add? Have a look at other orientalis in CNM to see if you can see the spots I refer to. No photo in Cogger and just visible in Wilson and Swan 5th Ed. p259
This individual was found in Mulligans Flat Woodland Sanctuary, other individuals have been found in vicinity, according to MFWS survey data. I understand your reasoning for C. Robustus. I plan to get better photos and confirm once it warms up.
Good luck. This image remains open on the subject for the time being. Remember both species will be there so you need to be sure of the paravertebral spots to confirm orientalis.