I put "Elle vient de me laisser un commentaire" and it was marked wrong. Is "tout juste" really necessary?
I assume Duo was expecting you to translate "just".
Note that you can use "tout" or not: elle vient juste de me laisser or elle vient tout juste de me laisser are equivalent. "tout" only adds emphasis.
I am not a native english speaker, but doesn't the construction "just + past" (in english) express exactly the passé recent? In this case, they should accept the translation without "tout juste".
yes, I just googled it and all the sites translate "venir de" as "just". I'm not sure how we'd be expected to know to add the emphasis.