I work for a company where we have contractors at the customer service centers. This is pretty standard for customer service workers. They handle reservations over the phone and customer support. The centers where they work are very locked down. They deal with customer names and credit cards as part of their jobs. They go through background checks. (It can be hard to get enough people who both apply and can pass the checks ) They cannot bring in phones, memory sticks, pens, or paper. they have to pass through a scanner to enter and leave the floor. They work on stations with locked down ports and restricted internet access.

I went there for a meeting but was not allowed on the floor because it was not pre-approved by security.

If the Apple centers where Siri errors are reviewed is like that, it would be hard to sneak recordings out.