I think "film vs digital" is much too broad a basket here. Even limiting ourselves to 35mm equipment, there is an astonishing number of variables.

For instance: are we comparing prints1? Both digital and film admit a huge variety of printing techniques. Hybrid methods go in both directions, scanning negatives for digital printing is probably obvious, but perhaps less so is inkjet production of large-format negatives used in carbon or platinum-palladium printing. Even on the less-exotic side, traditional darkroom prints will vary with the developer and paper used, and there are a number of alternative inks that can be used for high-quality B&W inkjet prints instead of the manufacturer's standard ones (which have several varieties themselves).

Leaving aside those questions, the short answer is this: digital B&W can be perfectly comparable to traditional methods in terms of the results. Also, digital B&W has value in and of itself, not just in reference to traditional methods (and vice-versa, obviously).

Personally, in terms of results, I don't find what hard evidence there is to be very compelling, as even objective differences are subject to individual taste. Differences in process are more obvious, but even more subject to personal preference.

And even those preferences might change depending on the context. Digital is indisputably more immediate than film, but if you're buying a photo rather than taking a photo, does that matter in the same way? Similar for darkroom printing; is the extra effort rewarding, or drudgery? Does it add value to a work, or is it irrelevant? Different people will come up with different answers to all of these.

So, after all of that, here's a couple of examples of objective, hard evidence:

• the red filter on the typical Bayer array doesn't allow you to reproduce the effect of deep-red filters on film2. In practice, you'll never know the difference.
• if fine detail/resolution is the criteria that trumps all others for you, then 35mm film is probably still a good choice. But even dedicated film shooters (like me) balk at ISO 12 for regular use.

I think you can see how given all the other factors, the objective technical details sort of fade into the background.

1 Yes.

2 For which I've unfortunately lost my reference, which was several years old and may have changed in the mean time. Hopefully the larger point remains clear, but if anyone wants to look up the requisite transmission curves, that might be interesting to know.