Crypto investor is so wrong on this. One, you cannot support EIP-999 but not EIP-867 (or a variation). If we are going to be in the business of rolling back the network for one person, we need to set the rules for rolling back the network. Two, his argument that there is no contention about ownership doesn't work. In fact, that should be an argument in favor of not rolling it back. There is no malicious actor benefiting from some people's hard work. Imagine if instead of the funds being lost, instead, someone had figured out how to steal or hold 500,000 ether hostage. In that case, the malicious actor gets to keep proceeds of his crime because we can't roll back the chain. If EIP-999 passes but not some variation of EIP-867, ether is done. If both pass, ether will always be second to Bitcoin. Neither passing is the ideal situation.