Happy 71st, Valérie Mairesse.

"I wasn't strong enough! I should have been able to stop them!"

TNG Season 4, Episode 2, "Family"

Robert Picard did nothing wrong.

Yes, he's a hard-ass and a bully. But imagine Jean-Luc is YOUR little brother. You'd love and hate his stupid nerd overachieving ass in equal measure, too.

Also I have to agree with Robert that synthehol is a sin against the ancient and noble human tradition of getting fucked-up on fermented sugar. The fact that Picard ends his vacation in La Barre wine drunk, covered in vineyard mud, testifies to this. Especially since it seems to be an important part of his recovery from the whole Locutus of Borg thing.

...Still don't understand what kind of Socialist space future lets a random French family maintain private ownership of a massive vineyard and associated estate. Maybe they have to open part of the house for public tours, or host weddings or something. Provide free wine to Starfleet admirals. I mean these people don't use money anymore, so they either harvest the grapes and make the wine with eager volunteers, or some kind of vinoculture robots.

The answer to this question, and why Robert's son acts like an unschooled Dickensian orphan, are not dealt with in this episode.

Picard in "The Drumhead" when questioned about the Borg under stress with far reaching ramifications: "You know, there some words I've known since I was a school boy. With the first link, the chain is forged. The first speech censured, the first thought forbidden, the first freedom denied, chains us all irrevocably."

In "Family":

Robert, wiping fake tears: "aw did sumbuddy get assimiwated?"

Picard:

There was enough downtime in "Best of Both Worlds: Part 2" for Riker to send such a message. In "Family", Robert aks Jean-Luc what "they" (they being the Borg, showing Robert knows that they were fighting the Borg) did to him. Robert says he doesn't precisely know what happened and knows that Jean-Luc was hurt and "humiliated". Jean-Luc tells Robert that he (Robert) knows what happened, which would seem to suggest that Robert was given some amount of information sometime before Jean-Luc arrived. Robert also doesn't seem that surprised upon hearing Jean-Luc talk about what happened. The surprised part, to me at least, seems to be about how much pain his brother is in and how human (emotional, breakable) his brother, who is notoriously closed-off and who he's been estranged with for years, is. Not what the Borg did to him. It should also be noted that Jean-Luc doesn't give that much detail about what happened. He didn't say that the Borg put their metal parts in him or that they invaded his mind and made him part of the Collective. He just says that they "took everything from [him]". He does not explain the process or the methods, and Robert doesn't ask or seem at all confused as to what the Borg are or what they do to the people they assimilate.

This seems to suggest that he knew some things, like Jean-Luc being taken by the Borg and made to fight Starfleet ("humiliation"). And that he knows, at least vaguely, what assimilation is.