Surely the more literal translation 'the man is a a man of science', which is perfectly fine in English, is also okay
"The man is a man of science" still not considered correct! Not nice!
Or "The man is a person of science", but was marked wrong.
I checked my answers and all I had for scientist was Savantul. Idid not know this word! That is very naughty of Duo. Reported.
The man is a man of science is still not accepted as of 11/02/20