This iPhone was lost or erased

I bought an iPhone on eBay with a damaged screen.

The seller stated that they had deleted iCloud and Find My Phone.

After replacing the screen it had the disabled for 24 million minutes thing (with the old users wallpaper blurred in the background) but showed a network/carrier connection. Several reboots didn't solve the issue so I restored in iTunes.

Now I have the 'The iPhone was lost or erased. Sign in with the Apple ID that was used to erase this phone.' message in iTunes.

After pressing Activation Help, the iPhone is asking me to contact the original owner to remove the device from their account.

Does this mean the owner hasn't deleted iCloud and Find My Phone or is this a standard security measure with IOS 9.1 even if they have deleted it?