"The science indicates..."

Yep, I read this too. That assertion, without enlarging on the "science" referred to or giving a link (which the article didn't), is weasel words.

The reason that this assertion should never be made is that it is impossible to gather scientific evidence for the efficacy of public mask-wearing without it being fatally clouded by confounding factors. "Masks save lives," and comments along those lines, are the absolute negation of science.

I wear a mask where I'm legally obliged to, and I would wear one if travelling on the Underground (which I may be doing quite soon as it happens), as the rules require. I don't break rules and don't advocate test anyone else should. But the usefulness of mask-wearing by the general public is either a matter of opinion or received wisdom. Take your pick.