You could not argue he consented, no. However it should be noted that there should be a distinction between legal definitions of a thing and the thing itself. "Real" rape - i.e. the subjective definition of rape that is useless in court because laws are as objective as possible - requires the perpetrator to either know the other person won't consent or at the very least not care whether the victim will consent. If a person has reason to believe the other party would consent - as in your description - most people would not subjectively identify that as "really" being rape, any more than a surprise hug and kiss to a spouse would in general be identified as sexual assault.

It's better to think of rape and consent like this: by not gaining consent, you leave yourself legally vulnerable to allegations of rape. However just because you did not gain consent does not imply you raped the person. It just implies that if the person comes forward and says you raped them, you cannot point to consent to prove you didn't.