Certainly a gratuitous apostrophe is the tiniest of nits. Great job on that review.
When I’ve written reviews, even though I grammar check, I find that I’m often making at least a few one or two character corrections in subsequent days. I know we’ve talked privately about some of my sources and foibles. In a post in a different thread, I talk a bit about how I used to work not merely in publishing services, but with SGML, XML, content editors, and a legion of precise grammarians that could probably be employed as weaponry.
In case you missed the link to Robin Cover’s hilarious discussion of the plurals and the apostrophe, I insert a pointer herewith: