They admit it in their email!!

We were sorry to learn of the incident you referred to in your email concerning flight QR473/6th September 2013. We understand that your co passenger, Ms. friend reported to have found a foreign object in his meal.
We would like to assure you that we are treating this matter very seriously and are currently investigating the matter with our caterers. As we are sure you will appreciate, all meals served on board Qatar Airways' flights are subject to stringent quality control and health and safety testing which is designed to prevent these types of incidents occurring.

Which Media?