What distros are there that normally dynamically link everything but statically link sudo? OpenSUSE, Debian and Ubuntu (the distros I have on hand) do not, at least.
Did you check the real sudo binary, or the setuid wrapper?
On my system sudo is `/run/wrappers/bin/sudo` but that is a setuid wrapper for `/nix/store/z008bzqrl2zc848gjhh04012jhxpl72q-sudo-1.9.15p5/bin/sudo` which is dynamically linked.