Why did I get the old restic docker container?

A year ago I have been playing around with restic using the restic/restic container. A simple call, like docker run restic/restic. Last week, I finished what I wanted to do with restic and I ran into a problem. After quite a bit of searching, I noticed this when I asked restic/restic for a version, and it told me:

restic 0.15.1 compiled with go1.19.5 on linux/amd64

That was old. So, I did a docker pull of restic/restic, and after that it says:

restic 0.16.2 compiled with go1.21.3 on linux/amd64

after which, luckily my restic problem was gone. But what I don't understand is why did I get that old container in the first place? Probably, the first time I ran it a year ago, it downloaded that image. But docker images did not list it. docker images -a does. But why. This is not an 'intermediate image' for which -a is intended. What am I missing?