Never noticed any moire myself.
OT, but I just have to say it. People, get the Sigma 14-24 2.8 either Canon mount with MC-21 or the new L iteration which has different internals and is much lighter. Either way, it is amazing with the S1-- especially w/ flat or neutral color profile. My new favorite lens and my 40mm 1.4 Art is no slouch, probably the sharpest lens I own, but that 14-24... wow! Seems just as sharp and probably sharper than many a prime crazy as that sounds. Will have to post samples...
And that orchestral footage above is stunning @ ISO 6400!