Monero was released with an intentionally crippled hash function. Whether the Monero devs realized it or not, the crippled hash was included to give someone an unfair advantage.
So BCN devs could have mined Monero faster. But BCN devs do not appear to care for Monero. Do you have anything that strongly indicates BCN devs mined Monero back then?
If somebody who was not involved in the creation of the hash function optimized it, the fact that it was intentionally crippled instead of accidentally crippled does not matter for fairness.