One of the three suicide bombers at the Stade de France appears to have been of Syrian origin (they found a passport, belonging to someone born in 1990). They have not been able to confirm whether the passport belonged to the person who committed suicide.
One of the three terrorists at the Bataclan is confirmed to be French. They found one of his fingers, and the fingerprint matched someone who was known by the police, but not security services.
Please don't confuse everything.
Just as, if none turn out to have been part of the immigrant wave, it will be conflated with that and the open borders issue.
Politics can be irrational even at the best of times, and this isn't the best of times...
The people and institutions pushing these confusions and trying to signal who The Real Enemy is know exactly what they're doing.
If both answers are "no", you are right about selective blindness. If not, it is you who are ignoring an angle.