Possible. But it's also possible that the founder of the team was a BSD person. You occasionally get cases where the preferences of one key person affects things in the long run. At this point I'm sure that they're baked in, because removing all that code would not be worth the effort too, so even if it was better when Netflix went online, that doesn't guarantee that it's still true today.
That being said, Linux is also used in a ton of places, including high network jobs. It would take a decent sized amount of evidence to convince me that all of those other places were wrong and basically only Netflix was right to use BSD in network heavy cases.
My suspicion is that either:
1. The difference is minimal to negligent, and not enough to justify mixed OS development
or
2. The difference is significant, but you have to be pushing your network much harder than most teams ever do for it to show up.