From what I recall, this isn't a new discovery - in fact there was even suspicion amongst some Bitcoin users that the Deepbit pool was using this strategy, though I don't think there was any real evidence.
I think it would be fairly easy to detect by just looking at repeated chains of consecutive blocks by same pool orphaning blocks from all the other miners.
That's also addressed in the paper - the pool does not need to declare that it is a pool, nor use the same IP address, wallet or similar to publish the block.
