Incorrect answer.
Karl's father Heinrich was not of "distant paternal Jewish ancestry." He was descended from a long line of prominent rabbis, with his father the latest in the line, and was raised Jewish, converting to Lutheranism shortly before Karl was born.
Karl's mother was born into a wealthy Dutch Jewish family, the one that later founded the Phillips Electronics firm. I have no info on whether she ever formally converted.
By Jewish law, of course, Karl was a Jew. Not to mention under the Nuremberg Laws, if they float your boat.
Karl’s mother was Henrietta Pressburg. Her grandfather was Jewish, which is the only confirmed Jewish relative.
She was Lutheran. Her baptismal records can be found by googling her name.
Karl’s father was raised in a secular household and converted to Luteranism before Karl was born.
Karl was baptised a Lutheran as a child, and had no Jewish training of any kind.
He was married to Johanna Bertha in a Lutheran church.
Looks pretty much like a run-of-the mill Lutheran to me.
“Not to mention under the Nuremberg Laws, if they float your boat.”
Actually, the Nuremberg laws required 3 (if you practiced Judaism) or 4 (if you converted out) Jewish grandparents.
The laws also considered parent’s conversions from Judaism valid if they occurried before 1898. (I believe I have that date right; I could be off a decade.)
Anyway, since Karl died way before and his father was a Lutheran, he would have been clear under the Nuremburg laws.