A teenager with a dairy allergy had told a restaurant's staff about his condition and was misled into thinking his meal was safe before he ate it and died from a severe reaction, a coroner concluded at a London court Friday, the U.K. Press Association reported.

Owen Carey died after celebrating his 18th birthday with a meal at a Byron Burger, a chain restaurant in London, in 2017. Investigators at the Southwark Coroner’s Court looking into Owen's sudden death found the teen had told wait staff about his allergy. He died after eating chicken marinated in buttermilk.

Owen “died from a severe food-induced anaphylactic reaction from food eaten and ordered at a restaurant despite making staff aware of his allergies,” Assistant coroner Briony Ballard ruled.

Ballard also found that the restaurant's menu made no reference to potential allergenic ingredient in the food selected, according to the U.K. Press Association report.

"We're very glad the coroner saw that and took it on board, because it was important to us that Owen said what he said at the restaurant," Paul Carey, Owen's father, told the BBC. "He knew exactly what he could and couldn't eat, and I think it's because we had drilled it into him from an early age."

After the ruling, Byron Burger's chief executive, Simon Wilkinson, said in a statement that the restaurant takes "allergies extremely seriously and have robust procedures in place and although those procedures were in line with all the rules and guidelines, we train our staff to respond in the right way."

Wilkinson added that the company "heard what the Coroner said about the need to communicate about allergies," and that "it is clear that the current rules and requirements are not enough and the industry needs to do more."

The incident prompted the Carey family to call for a change in British law requiring restaurants to clearly label all allergen information on each individual dish on their menus.

"His death should not have happened," Emma Kocher, Owen's sister, said outside the court on Friday. "It is not enough to have a policy which relies on verbal communication between the customer and their servant which often takes place in a busy, noisy restaurant."

"There are hundreds of thousands of people in this country who've got allergies who are very scared or their parents are terrified for them to eat out in restaurants because that is the key place where they are at risk," Moira Carey, Owen's mother told the BBC.