Nice job!
It would be interesting to figure out the mechanism of Thomas' appearance in the hall. Did he always appear in this hall or he made an exception for Clara?
Or maybe he shifted the space-time continuum and moved Clara in a different time, before his accident and that's why Kelly didn't see her.
Then again, maybe it was a hired actor by the manor management to enhance more visitors to the manor. Sort of like in this SNL skit