I'm absolutely sure that he'll have been through all the necessary checks before being appointed to his position; if you think that the company have done so incorrectly, contact them.
This person may have a condition or disability, but it might not be something that would stop them from doing their jobs. Would you be less likely to trust your GP / Dr if they were in a wheelchair or chewed the side of the mouth when they were nervous?
I'd rather travel on a bus where the driver was a little slow at giving tickets, etc. than someone who didn't care to wait for you to sit down before sticking their foot to the floor and me ending up on my backside.
And please, do not complain because others have a job while you are struggling to find one - better yourself.