As I read that post, the circumvention applies only to a throttling control, not an overall access control. Since it should have been just as easy (if no easier) to simply block unofficial clients instead of throttling them, it seems like a clear argument that Google does not intend to block 3rd party Downloader, but merely give preferential treatment to first party ones.
If you by that argument. Then bypassing the protection might be illegal, but would not be a copyright issue, and Google would be the only one with standing to sue.
If you by that argument. Then bypassing the protection might be illegal, but would not be a copyright issue, and Google would be the only one with standing to sue.