how can you hide a fighter jet behind a surveillance plane ? not very good surveillance
Position the other plane between you and the incoming missile, depending on the age/guidance system it will home in on them instead, especially if you use countermeasures and they don't have any.
It's similar to how a British cruiser in the Falklands ended up accidentally destroying the cargo ship carrying all the task force's supplies by deflecting an incoming Exocet into it.
Yes, pretty much this.
The S-200 is a really old missile system, good back in the 60's, but compared to the new stuff today, it's old, obsolete and stupid.
Once the missile is fired, it has no way to tell friend or foe, it just tracks for the biggest signal it can detect and since the II-20 surveillance plane is a huge target compared to the smaller F16's and if they positioned between each other, it's easy to understand why it happened.
The blame should be shared equally between Israel and the Syrian crew who fired it. The Syrians should had detected the plane and confirmed who they are. The control units to fire the missile are really basic, the screens themselves don't really show who is who, but the system does have an IFF system in place to stop this happening.
Anyway if in doubt, they should had been made aware that an II-20 was in the area and should had that noted and should had confirmed with their command units who should also know this.
The biggest amount of blame then should be given to Israel who clearly know the II-20 was there and know that their flight path would put them between the AD units and the Russian plane between them. Needless to say, very smart of them to use it as a decoy, but that's what you expect from Israel.
They have a history of playing very dirty, they like to use IFF pretending to be Americans in the last few years.
The II-20 itself should had countermeasures, maybe they used them, maybe they didn't, but am going to also assume it was a very chaotic situation for them, last thing I would had thought they be expecting.