Apparently Donner just didn't like Prins because according to Chessmetrics Prins highest rating was a pretty impressive 2604 in December, 1951. His best performance rating was in the Zonal tournament at Bad Pyrmont when he scored 7.5-4.5 for a performance rating of 2624.
Lodewijk Prins (January 27, 1913, Amsterdam – November 11, 1999) was a Dutch player and International Arbiter. Prins was awarded the IM title in 1950 and was made an International Arbiter in 1960. In 1982 FIDE made him an Honorary GM.
Prins represented the Netherlands twelve times in all Olympiads from 1937 to 1968 and won two individual silver medals (1939, 1950) and one bronze (1968). After the German invasion of the Netherlands in May 1940, his name did not appear in any tournament in the occupied Netherlands because of his Jewish origin.
After the war, he took first place at Hoogovens Beverwijk in 1948 and at Madrid 1951 ahead of Herman Steiner, Herman Pilnik, and Ossip Bernstein. Prins qualified for the 1952 Interzonal and was Dutch Champion in 1965.
The following game played in the open tournament in Travemunde in 1951 has been described as a “pure circus” that was “almost contrived.”
1) Lothar Schmid 9.0
2) Herbert Heinicke 8.0
3) Lodewijk Prins 7.5
4-5) Gerrhard Pfeiffer and Rudolf Teschner 7.0
6) Efim Bogoljubow 5.5
-8) Ludwig Rellstab and Haije Kramer 5.5
9) Jens Enevoldsen 4.5
10-11) Fritz Saemisch and Georg Kieninger 3.5
12) Erik Richter 0.5