The question was whether the OP gave the concierge all the facts. If the OP said, "I have park hoppers and need to ... " then that's not really fair to the concierge. There are exceptions and conditions, so it would be unreasonable, in a casual verbal conversation, to expect the concierge -- someone who is expected to converse with guests in a casual, non-legalistic manner -- to include disclaimers and codicils. I can tell you from personal experience, how being so meticulous about the guidance and information I provide here on the DIS evokes negative reactions from some people -- some people simply react negatively when they perceive that they are being provided information in that manner, criticizing how the person is "covering their tail" and such. I'm not working for anyone, so I don't have to worry about anyone complaining about how cold and factual what I write is, but be sure that a concierge will be fired if too many people complain that the concierge is "covering their tail" like that. Playing the odds, it is safer to play it the way the concierge did, because it is more likely that if the consumer complained about this situation that the manager will recognize that the fault is their own (because of the direction they've provided regarding the rules and the manner in which information is to be provided to consumers), not the concierge's.
I have to disagree. If you want to hold a company's feet to the fire for such things, then get it in writing. Too many consumers are too quick to exploit such things to expect casual verbal conversations, where you cannot prove whether the consumer provided full and complete information, to constitute a binding contractual agreement, or even a moral obligation. Only if the consumer provided all the information necessary to be able to provide the accurate information, and the consumer asked the person providing the information whether that they were absolutely sure that the information would be honored, would such an expectation be even remotely reasonable, from a business standpoint. Consumers want the convenience and efficiency and "feel-good friendliness" of casual verbal communications so they must accept the natural ramifications of such an imperfect means of understanding the actual situation.
She was told she couldn't, when she bought the tickets I am sure that there was a disclaimer. Granted the CM shouldn't have told her yes without knowing all the facts, but when she asked did she specifiy that she had discount tickets? If not thats on her, not him for misinforming her, since to his knowledge he probably assumed that she would have mentioned they were discount tickets when asking.
I hope your day has gotten better. It is very frustrating when a CM gives you false information. 
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