Yes, this is definitely C Dorian. The bass and main riff is centered around a C Blues lick, so that’s kind of solidifying the overall sound around “C”. Also they are bending the Eb up a little to add that extra blues flavor. And then the chords are Bb – F which kind of a I-V in Bb Major. But again, since they are centering around “C” in a Bb major harmony, it comes out to which mode? That’s right, Dorian.
Another SUPER easy way to identify Dorian is when you have a minor key/lick and then you have a MAJOR IV chord. The IV in C is F major. So a C minor lick, Bb Major in a C minor sound is diatonic, and occurs naturally in a C minor scale. The F major chord raises the Ab (which is normally in C minor) to an A natural making it Dorian. Normally the F chord in a C natural minor scale is F minor.
C minor w/ flat 6 (Aeolian) C D Eb F G Ab Bb C
C minor w/ natural 6th (Dorian) C D Eb F G A Bb C