Munich pilot reports [Oncoming Plane]

[Matt33]

Some more quotes from that article:

Dr. Buettner is willing to contact the pilots of the other aircraft identified on ADS-B to clarify whether they were possibly flying without external lighting or whether there was a technical defect.

That's not the question. The question is wether they left on their landing lights. Those would be so bright that they probably outshone all other airplane lights and the silhouette of the airplane.

According to the anonymous pilot, however, no known aircraft system is capable of simultaneously activating landing lights, deactivating all other lights (navigation, position, strobe, cabin, logo) and switching off the transponder, so that no TCAS signal would be displayed either.

Again, that's not the question. Nobody is alleging that lights or anything had been deactivated. There is only one question, were the landing lights left on?
The author later says that this might have been the case, but then:

The smaller lights here would correspond to the lighting at the tips of the wings. However, in order to achieve a light configuration like the one in the photos, this oncoming aircraft would have to be flying at a very steep angle of approximately 45°.

No, the smaller lights probably were reflections as Mick explained. All other smaller lights on the airplane were overpowered by the landing lights.
For some reason the author of GreWi chooses to lead a strawman debate.