It seems to me like this was all being done privately until Mr Hamacheck got a lot of attention and the wrath of HN on his side. I don't see how the other founders had much choice but to explain their side - otherwise they look like a cold, heartless corporation. The original story seemed very much like a guy trying to run a business was blindsided by a huge, funded company. But after the response it seems clear that he had been communicating with them and even proposing business relationships before even launching his product.

My opinion of the situation was definitely changed after this response letter. It kinda goes to show that these kind of arguments make everybody involved look bad, though.