I think the check, not drop gear for classes not present, is done for operations only
I remember several times where some BH gear dropped with no BH present on the group when doing flashpoints
I really need to go find the posts where they introduced this feature so I can link them, since people are apparently not listening.
All flashpoints, whether story mode or hard mode, are supposed to drop class-appropriate gear.
The system does not work perfectly and will occasionally drop gear for classes that are not present.
I did 10 solo runs of the Black Talon in a row on my Juggernaut, and I ended up with 5 pieces that were not Juggernaut gear. 5 out of 46 drops(got 6 non-boss zone drops) in a completely random drop system is almost impossibly low. I have some theories about what might cause the discrepancies, but I'm not a programmer so I can't really say, but the system is designed to drop only class-appropriate gear in all flashpoints, it's just slightly broken.