There have been many selective quotations from SERA trying to prove a point but perhaps they should be the relative quotations:
GM1 SERA.5005(c)(3)(iii) Visual flight rules
NIGHT VFR ON TOP When flying in airspace classes B, C, D, E, F, or G, more than 900 m (3 000 ft) above mean sea level (MSL) or 300 m (1 000 ft) above terrain, whichever is higher, the pilot may elect to fly above a cloud layer (VFR on top).
When making the decision on whether to fly above or below a cloud at night, consideration should be given at least but not limited to the following:
(a) The likelihood of weather at destination allowing a descent in visual conditions;
(b) Lighting conditions below and above the cloud layer;
(c) The likelihood of the cloud base descending, if flight below cloud is chosen, thus resulting in terrain clearance being lost;
(d) The possibility of flight above the cloud leading to flight between converging cloud layers;
(e) The possibility of successfully turning back and returning to an area where continuous sight of surface can be maintained; and
(f) The possibilities for the pilot to establish their location at any point of the route to be flown, taking into consideration also the terrain elevation and geographical and man-made obstacles.
There is NO mention of maintaining visual contact with the ground - in fact (e) indicates that it is not necessary