I thought I was feeling pretty comfortable with the differences between the preterite and imperfect but this one has stumbled me.
"He had an English girlfriend" you have translated as Él tuvo una novia inglesa.
But I would see this sentence as: "He used to have an English girlfriend" (Él tenía una novia inglesa) which would require the imperfect, as it is implied that he no longer has this same girlfriend.
Have I missed something or are both acceptable?