Your wording seems to imply that under this scenario, Obama would have been SOME KIND of citizen, just not natural-born. You are wrong, if this is your message. But, in fact, under the scenario presented here, Obama is not ANY kind of US Citizen, natural, native, naturalized, or statutory. He would have been EXCLUDED from citizenship entirely.
No, at the time of his birth Obama was not a U.S. citizen and because his father is not a U.S. citizen he never could have been a natural born citizen even if his birth had been in the U.S.
That is unless his relatives went to the trouble of applying for a COLB from the state of Hawaii. Of course this would have been fraudulant, but who would have bothered to look into that at the time?