I love Mathews's stuff, but he needs to research this topic more before telling others how things work.

No, Core Devs cannot "change a line of code" to prevent U.S.-based miners (by IP address) from attacking.

No, empty block attacks (with 51% or more) would not be letting blocks be mined by any other miners, so it is truly 100% empty for 100% of the blocks, as long as the attacker has 51% of the hashrate.

And there were other head scratchers in this.