So, over time, chicks unrelated to each other began to not peck at a given object as much, given a negative stimulus. Results aren't really in question, it's the "oh, they're all psychically linked" that's pretty much in question. There are multitude of other explanations possible, including involuntary corruption of the test by the experimenter (see also: the 'counting' horse that was actually responding to visual cues from its trainer, and not actually counting).

See also: Venkman and the pretty girl at the beginning of Ghostbusters

I tried to find instances of other scientists

Morphic resonance (and the 'morphogenic field') is an old idea from before we even knew about chromosomes, let alone DNA: it's a lot like how homeopathy was a big thing until we kind of figured out that bacteria caused disease.. A low statistical correlation with no corresponding replication with a high probability of accidental corruption by the original experimenter does not a compelling argument make.

Your 'unbiased look' at the event is by the guy himself. I don't think that really counts..