If we’re talking about clarity I think there’s some merit to the claim. It has tense markers that English lacks which buys you information in the conjugation about tense, gender and speaker. And unlike other Latin languages you aren’t able to drop the subject and just rely on the verb to convey it which forces clarity one could argue. You get the best of both worlds for clarity though the worst of both worlds for conjugation complexity and overall verboseness.
At least that’s my attempt to defend the GP’s statement.
English has (at least) four constructs to talk about the past: "he went", "he was going", "he has gone", and "he used to go". All four mean something clearly different. French meanwhile only has "il allait" and "il est allé" (and, technically "il alla" though nowadays that is basically only used in writing and its meaning is not clearly distinguishable from that of "il est allé").
It's easy to find examples of distinctions made by French that English doesn't make, and vice versa. That doesn't mean that either language, overall, tends to express concepts more precisely than the other.
At least that’s my attempt to defend the GP’s statement.