But it's not slander to tell the pastor true things about your small group members, and in most cases, not even considered gossip!
It's kind of depressing that your experience, which I assume came well after the Weaknesses paper, is so similar to my experience in the late 70's.
Here's an example from back in my day. On one occasion, during a meeting with the sisters I lived with, I was trying to seek their advice to deal with a puzzling encounter I'd just had with a neighbor. Before I could fully articulate the problem, one sister cut me off with the remark, "Is this gossip? Because I don't want to hear it." Yet, as it turned out, the same sister was functioning as an informant to let the deacons know what was happening in private among the sisters.
So when some of us old-timers say that there are problems in the very DNA of GC, we're not just making it up. These problems have been handed down and institutionalized since the founding of the movement.