The issue involved someone, apparently in Russia (Russian language forum site), who discovered that the bytecoin miner (subsequently cloned to MRO) had apparently been de-optimized prior to public release and could be made several times faster with relatively simple changes. It was one of the MRO developers (NoodleDoodle) who promptly released an un-deoptmized miner (subsequently back ported to bytecoin), and later released additional optimizations.

You won't find a more fair launch of any coin no will you find team behind a coin with more integrity than the Monero team in my opinion (though as a minor disclaimer, I don't know all of them outside of our work on Monero -- the work on Monero has been 100% above board and community-focused).