RUTHLESS: Expedition scarab dropping in Map although Expedition blocked in Atlas skill tree

Title says it all.

I am playing Ruthless, Settlers league.
In a T14 Ashen Woods Map (magic), an Expedition scarab dropped.
The one that says "Area contains an Expedition Encounter"

In my Atlas skill tree I have the TRADE EMBARGO node activated. That node says that in my maps, no Expedition scarabs can be found so I expected none to show.

To clarify: This was NOT a Kirac mission. It was a magic T14 map I ran just by itself with Maven activated. And yes, the right skill tree was activated. I only have one skilled, never created a second one, never swapped.

https://rapidshare.io/1MvD/Bug-Expedition_scarab.jpg

Scarab blocking only applies to natural drops. It is still possible to get blocked scarabs from various mechanics and you'd have to recall where the scarab came from to know if it one of the mechanics that bypasses blocked nodes.

I don't recall the full list of mechanics that bypass block scarabs. I'm pretty sure on Betrayal, Eldritch altars, boss atlas notable (not sure if this exists in Ruthless), and incubators. I can't remember on strongboxes and any others.

Update:

I just played a T16 magic map, PIT. With Maven witnessing.

Boss dropped a BREACH scarab. I have Breach disabled in my tree.

I am assuming that this is a natural drop and it shouldn't happen.

Or is it a "Maven- induced" thing and he drops this specific item because Maven is witnessing the fight?

Are you specced into Chittering Champions for 10% scarab drop (not the same as increased chance) per final map boss (multiple with Maven passives)? I believe that node causes the map bosses to bypass blocked scarabs as those are not natural drops, they come from an atlas passive.

If not, I recommend a screenshot of your full atlas passive tree.

Good point.

I am indeed specced into that node.

Bit tricky to determine what is a natural drop and what not. Didn't even think about that. Thanks for pointing it out!