The legal aspect was always redundant, to my mind. It evokes consequentialism,
a pragmatic "If you get away with it, great". By present laws.
I agree with that, and think it's a great point, but the legal aspect is not without relevance to the total moral decision. If we were discussing whether one ought to pay income tax, we might fairly conclude, "No" if we disregard the subsequent prison time as an affecting aspect of reality. It is an element of reality, so when making a personal moral decision you must take it into consideration or you risk not making your life better.
Likewise, when deciding whether to take someone to bed, the possible legal ramifications should be weighed. Currently, a man has to make a character decision about the woman as to whether or not she is likely to ruin his life and have him sent to prison at her whim. If the legal definition of rape was moved to "the point of genital contact," then it would be the woman's responsibility to ascertain before hand whether or not the man is sensitive enough to stop mid coitus upon request before she let's him engage in the sex act. So, in effect, Peikoff is saying that, yes, morally, a man ought to stop when requested, but no, it should not be "rape," a legal term, since to classify it as such creates a hugely one sided and irrational legal circumstance that's untenable. It's only purpose, really, is to allow women to have sex with men whom they don't know very well or just met. The cost of this privileged is paid by uncareful men with ruined reputations and 20 year prison terms. With Peikoff's alternative, women can predict with a fair amount of certainty whether a guy is the type to stop on request, if they take the time to get to know him before inviting them to bed. I don't think that's an unreasonable requirement and don't think it's much of an issue, honestly. In my life, I can count on one finger the number of times a woman has asked me to stop. So anyway, I see no inherent contradiction in it being a morally correct action to stop upon request while denying that it is a crime that can be proven by a woman's claim alone.