“Also, with the plastic barrier between driver and backseat, how could the dog be any kind of threat? ”

From your following line, I am not sure if this was being played as a joke. If it wasn’t, I would point out that phobias are irrational fears. Check out Coulrophobia or Triskaidekaphobia. It is unlikely that a suffer would ever be truly threatened by what triggers their fear.
A least unless they we here: http://www.imdb.com/title/tt0095444/

No mention of if Ahmad ever previously documented this problem to a doctor. Would seem to tip the case if he just decided to mention this debilatating fear right when he arrived at the blind guy’s home. Also, with the plastic barrier between driver and backseat, how could the dog be any kind of threat? Unless it’s a service teacup chihuaha. That scares me as I have a fear of tiny vests.

ps – I also have a fear of negative replies to my comments, so if you want to avoid a letter from my quack attorney…

To paraphrase George Orwell, all disabilities are equal, but some are more equal that others!

That one is easy. Whoever has the most money to pay the lawyers, loses. usually that will mean the employer or business.

In a truly public place, you may have to come up with a way to blame the local governing agency. I am really surprised that folks haven’t started suing cities for violating the rights of nicotine addicts with the extensive public bans on smoking.

Now we just have to determine who is responsible for paying for phobia treatment. The cabbie has the greatest incentive to pay for and make such therapy effective to achieve the immediate reward of continued employment; then again, he may have other incentives or agendas to ensure that he cannot be cured of the phobia affliction.