In fairness, I knew bugger all about Staffordshire or veterinary science for my first two editorial jobs; that made me check more often.
This is a big problem in medical journals - the salary for an editorial role is a mere percentage of that you’d get for being a vet/doctor/nurse/consultant. However, in an ideal world you’d have medically qualified journalistic staff, but if they have the qualifications for a, say, £120,000 job, why would they do a £20,000 job? (Graduate journalist jobs are about £12,500 - if you’re lucky).
Medical journals are peer reviewed which deals with the hard science (well, most of the time) but having a medical degree does not mean you automatically have an innate grasp of the English language. Sub-editing and proofreading is an artform, enhancing without diminishing. Sadly it’s not one that’s valued much these days...