I always believed that he was, but he was fairly light and not that fast, I think there is a possibility that he used and had alot of strength in his punches and thats why all the guys he faced said they HURT the most but they might not actually be as powerful as say a Tyson punch!? (Which wouldnt hurt as much but was more likely to put you to sleep)

I look at Tyson putting away huge guys and then I look at Earnies KO highlights and they arnt anywhere near as impressive as in he didnt put away many big guys like Tyson did.

I dont really know though thats my uneducated guess, what do you think?