Murder of Crows starts out with various experimenters donning a crudely made rubber mask as they catch crows. They then release the crows, who afterwards naturally recognize the mask as a sign of danger no matter who wears it. The "scientists" then proudly announce that they've shown that "crows recognize individual faces".
Which they haven't. And it's pathetic that they can't even correctly formulate what they've done here. What they've shown - technically, factually, very simply - is that crows recognize a particular MASK.
If these people can't be precise, to a minimal level, about it is that they're doing in an experiment - they aren't scientists. Surely enough, crows CAN recognize faces. But you weren't doing a test as to that effect! You were testing out a mask, not a face.
I assure you that if you run a test as to whether crows can fundamentally distinguish between a human face and a piece of rubber - the crows will pass with flying colors. These are the same creatures that can distinguish between a real gun and a replica of that very gun.
My point is twofold. Firstly, crows have excellent and far-reaching recognition abilities. They'll recognize various trivial things as a part of their struggle for survival. This has been known for a long time, and demonstrated many times. Secondly, the test described above simply confirms a facet of that phenomenon - but not at all the one that the experimenters claim. Don't say that you've proved that crows can recognize faces when you were actually busy confirming that they will recognize a specific piece of rubber. Run a test with actual faces - it's not that difficult.
There are other inaccuracies and rather ignorant comments throughout this Nature episode. Moreover, the creators don't give you one bit of info on things that would have made the documentary properly interesting, such as the crows' anatomy, physiology, and evolutionary history.
I'm giving the film 3 points for the inherent coolness of the crows, but this inept documentary doesn't even remotely do justice to these elegant, clever birds. 3/10.