Testflight internal tester installed app exceeds 10 device limit

Question

Apple clearly mentioned on their page here

\"Each app can be tested by up to 25 members of your team who have been assigned the Developer or Admin role in iTunes Connect

Answer 1

You're right, according to Apple, you can install in up to 10 devices. I think that maybe he installed the app twice in the same device

Answer 2

As mentioned by apple ->

Installing Beta Apps

You can install beta apps on up to 30 devices.

See this - https://developer.apple.com/testflight/testers/