I'm going to step in here. I am trained as a scientist and therefore may have a more narrow definition of science.
The original work on octopus laterality was lead by Dr. Ruth Byrne and as done with controls and attention to observation biases. Two papers were published in peer reviewed scientific journals - while far from perfect, this peer review system is the best available method.
If you use Google Scholar and key words “octopus, laterality, byrne” you can find the original abstracts.
This work was covered in the media fairly accurately. This isn’t always the case.
On to the current work.
Be careful with reading to much into this recent study - or at least the reporting on it.
Here are my concerns:
Arms and tentacles are frequently confused - not a big deal and this could be a mistake the journalists, not the scientists.
Of much more concern is "Some previous studies had found that octopuses favored one side over the other, and the explanation for this was that some were shortsighted or had visual impairments." If that refers to Ruth Byrne's work, the explanation "some were shortsighted or had visual impairments." does not fit my understanding of her work or octopus vision.
There are papers on octopus arm use, for example: How Do Octopuses Use Their Arms?
JA Mather - Journal of Comparative Psychology, 1998 and a lot of recent interest in the biomechanics of octopus arms. I’ve not read this in a while but am wondering if the results of this recent study are new.
Observer bias/confusion could be a problem depending on how it was handled. We all interpret things differently. When several people are recording behavioral data, it is standard practice to test them against each other so something could be said about their consistency when scoring the same thing.
It looks like the work is prelimary (not yet published in a peer reviewed journal).
The majority of scientists do not release prelimiary results. Prior to publishing results most scientific journals require that the scientists sign a waiver that the results are new and not published elsewhere. If hey have already been released they are not new by definition. It is for this reason that the news of Dr. Kubodera and colleagues photographing the first live giant squid was not reported until a full year after the discovery.
Does this mean this work isn't of value? That a very different question, and my answer is a strong NO. I would classify this study as education. It helped to get people to look in detail at octopuses (which promotes public education and involvement). Education is a very noble goal! Also keep in mind that my defintion of research, as a scientist, is narrow. Getting a lot of people to look at octopuses in an organized way is a very good thing which I fully support.
Bottom line: To me this article provides some useful ideas to think about (especially the "2 legs idea) but I would be careful with the methods and conclusions. If the spin is that this is recent research, there are a lot of things that bother my inner scientist.
Disclaimer: These are my personal thoughts and do not reflect the ideas or views of any institution or group that I am associated with.