What is the ruling on ejaculating by hand-play during fasting due to ignorance of the ruling?

If a man fondles his wife during the day in Ramadan and emits semen, his fast is broken, and he must make up for that day without expiation. If the woman emits (fluid) because of this, her fast is broken. However, if he emits madhy (pre-seminal fluid), his fast is broken according to Imam Ahmad and Malik, but not according to Abu Hanifa and Al-Shafi'i, and the latter is the more preponderant view.