GR translation: For all Slothrop knows he’s an agronomist

[Mike Jing]

P214.8-21  During the lessons he will often look over and catch Sir
Stephen Dodson-Truck consulting a stopwatch and taking notes. Jeepers.
He wonders what that’s all about. Never occurs to him it might have to
do with these mysterious erections. The man’s personality was chosen—
or designed—to sidetrack suspicions before they have a chance to
gather speed. Winter sunlight hitting half his face like a migraine,
trouser cuffs out of press, wet and sandy because he’s up every
morning at six to walk along the strand, Sir Stephen makes perfectly
accessible his disguise, if not his function in the conspiracy. For
all Slothrop knows he’s an agronomist, a brain surgeon, a concert
oboist—in that London you saw all levels of command seething with
these multidimensional geniuses. But as with Katje, there hangs about
Dodson-Truck’s well-informed zeal an unmistakable aura of the employee
and loser. . . .

The part: "For all Slothrop knows he’s an agronomist, a brain surgeon,
a concert oboist", this is just speculation, Slothrop does not know it
as a fact, is that correct?

I am fairly certain the published translation is wrong again, but I
just want to be absolutely sure.