Having flown for some time when there were not so many rules as there are now I have done scores of IMC take offs during the day and night. The conditions have ranged from blowing or laying snow, Norway and the UK; blowing or enveloping dust, Cyprus, Middle East and Australia; heavy rain, Australia and the South Pacific and Fog, Everywhere.
The golden rule is: Do Not Look Out of the Cockpit until you are established in the climb.
The visible snow, dust, raindrops and mist swirling around the cockpit will create an overwhelming impression that the aircraft is going the wrong way. At night the stuff going through the landing light beam will double it. If one does not ignore this than the situation can get out of hand so the only safe course of action is not to look.
Whether this effect had any bearing on this case I will not speculate but if somebody remembers that rule in the future then that is enough.