I agree, but in this case I'd say the problem seems to be 50/50 cofounders with no clear hierarchy for decision making. I've been burned by this too many times

I agree, but in this case I'd say the problem seems to be 50/50 cofounders with no clear hierarchy for decision making. I've been burned by this too many times not to insist on a clear discussion up front on who has "last call" on product issues. Of course something like the quoted interaction is a symptom of a dysfunctional relationship and probably has very little to do with the actual issue at hand.