Sure; though, as I mentioned before I did try again and it did work. Doing a pull once more I failed with:
guix substitute: error: TLS error in procedure 'handshake': Error in the pull function.
substitution of /gnu/store/k1da7bv579d8gvwdrakd9l4hxswknff2-guix-module-union failed
guix pull: error: some substitutes for the outputs of derivation `/gnu/store/k2gdq7ahjaqmdgjr9xwywqpxvzazn467-guix-e07573432.drv' failed (usually happens due to networking issues); try `--fallback' to build derivation from source
As with before, I was also able to succeed on a subsequent pull; but this error seemed to be handled better as it suggested both the cause of the problem and a possible solution.