tl;dr: @lukedashjr decided to use a testnet4 block hash as the random beacon to pick BIP-110-chain's new PoW function. An absolutely batshit decision. It's clearly possible to manipulate that by just mining blocks with the right hash. Mining a testnet4 block has a trivial cost. So mining one with a specific last byte in the block hash – thus forcing a particular PoW choice – also has a trivial cost. When Zcash did something similar for a trusted setup, they picked a Bitcoin block in the future, and they specified that the block hash would in turn be re-hashed 2⁴² times¹ to ensure that absolutely no-one could possibly pick the value in advance (that's a 2-3 weeks of sequential computation). There's two possibilities here: 1) Luke is incompetent. 2) Luke is malicious, and is trying to pick a specific PoW. The possibilities are not exclusive. 1)