To Rococo: Your notes do not address the question and the model that is referred to in the article. To be sure we are talking about the same thing, the question is whether the article http://arxiv.org/abs/1406.0901 (published in Found. Phys. 2016) is correct in its main claim, namely that local hidden-variable models that include a background field are possible (and plausible) after all. This is important, since it goes against Bell’s theorem (as it is usually understood). Concerning your notes:
1. You say “What one could hope is that analysis of these droplet experiments leads to a plausible model for how this assumption [measurement independence] could be violated.” My answer: this is precisely what is what is proposed in the article, in a detailed way. If a background is present (e.g. one that has similar properties as the fluid’s pilot wave in the droplet experiments), the article shows that measurement independence and the Bell inequality can be violated. The arguments are pretty straightforward, so if you find a math error or an unphysical assumption, I would be much interested !
2. You say: “The authors show that suitable background correllations could in principle lead to a Bell violation in a droplet experiment, but they do not specify what observable would actually exhibit these correllations”. The topic of the article is not to argue that a Bell inequality can be violated in droplet experiments. The article concerns the admissibility of background-based hidden-variable theories for quantum mechanics. Only as a corollary, in a few lines, the article suggests that a Bell inequality can possibly be violated in a Bell-type experiment on droplets, because such systems contain a background (the surface or pilot wave on the fluid film).
3. You say: “one could in principle imagine some weird electrical surge that is just right to trick us. My personal feeling is that until I see a plausible physical model for such 'conspiracies,' I do not find them very interesting.” The goal of the article is to show that there is nothing weird to be assumed: just a background field (the physical vacuum, a zero-point field, a dark field,…). Note that that is all what quantum field theory is about. There is no conspiracy at all going on ! Really, your “personal feeling” is the standard opinion; but it is precisely what the article tries to counter, by a straightforward physical model. If you wish to help to assess the validity of the model, you would have to dig into it, and assess the validity of the physical assumptions and of the math.