Should restaurants be able to tack on an additional fee for "special prep" when a customer has a food allergy & requires individualized service?

In responding to another question about having a food allergy & eating out, it reminded me of a similar situation where I eat lunch. Lady comes in mid lunch time asking if her favorite meal comes in contact with any peanut product as she could die IF even the spoon came in touch with a peanut product. The waitress stopped waiting on anyone else to go back to the kitchen to inquire about the peanut food allergy. When she comes back, she informs the lady that the menu item she’s asking about “might” indeed come in contact with a peanut product. The waitress politely asked her if she would like to choose another item even guiding her to the ones that wouldn’t have “any contact”. The woman became livid because she couldn’t get the meal that she wanted. She then began to explain to the waitress how it could be cooked to where it would be safe for her to eat. In the meantime, the waitress’ tables are backing up while she’s still trying to please this one lady. This lady grew louder & louder in her disgust of the place to the point that the owner emerged from the back to tell the waitress that she needed to continue to take care of her customers & he would see if he could make this lady happy. No matter what he offered to make for her that he could guarantee would be safe for her to eat, she didn’t want to hear it. Thirty minutes later, the owner hadn’t been able to please this lady & finally in complete frustration he asked her to leave so he could get his restaurant back under control. She blew her top & argued that he was discriminating against her & her food allergies. He apologized to her & explained that he wasn’t willing to take her life in his hands by even trying to prepare a meal that would fit her dietary needs. She got up & stormed out screaming that she’d NEVER step foot in his place of business again. All the patrons whose meals had been delayed or ruined began to applaud. Now, had he stopped the rhythm back in the kitchen to specifically make exactly what she needed & delayed any orders coming out behind hers, should he have been able to charge extra for her meal??? I’m ordering a menu item “as is” & I can’t get it because the restaurant would have come to a halt in order to make her a specialty item. IF mine comes out so late that I’m unhappy, I could leave before I get my meal & the restaurant is losing revenue by stopping production for “just one” person!!!

Another place where I eat has signs all over the place saying that their food might be contaminated with peanut products & IF you want to wait for a special prep that there could be a considerable wait time & a $2.00 up charge for special “off menu” prep.Personally, I think that $2.00 in exchange for my life is a bargain but I’ve heard many complain that they are being ripped off!!!

What are your thoughts???