I have a question for SAM enthusiasts in this forum.

Youtube is full of videos showing the destruction of Pantsir systems in Syria in March and most recently in Lybia. While in some videos the Pantsirs were killed parked near buildings or in transportation, at least couple of them show hits on Pantsir in engagement mode, with a rotating radar or even firing missiles.

Here is one such example:



It has been claimed that these Pantsirs were hunted down by Bayraktar drones. I have a couple of questions:

1) how a relatively large, slow flying drone got so close to the SAM system, that was designed to combat exactly this type of targets, undetected? Are they flying so slow, that the Pantsir radar cannot see it (Doppler filter)?

2) have these Pantsirs been blinded by ECM? I've seen comments on the effectiveness of turkish Koral jamming stations, but I find it unlikely, that they put these kind of stations closer than the radio horizon of the radar. Maybe on the country border, but not so deep inside the enemy territory.

If neither 1) or 2) is correct, then what could be the other possibilities for such repeated defeats? Does Pantsir have a fundamental technical weakness that was exploited? Were these SAM crews totally unfit for the job (lazy, stupid, or both)? Or was there some kind of a very smart tactics deployed by adversaries (like swarming with multiple drones, until the Pantsir shoots all its missiles and auto-cannons and the last drone gets through)?.