I'm a little confused as to how restriction enzyme works. If you use two restriction enzymes, at the same time, to digest DNA, is it possible that one of the Res Enzyme cleaves part of the DNA off and the second enzyme further shortens the already cleaved DNA. I.e if the sequence is GATCGGATTC from the first digestion, is it possible that the second digestion may further cleave the sequence above, making it shorter? i.e.
GATCGGATTC---> GAT/CGGATTC
GATCGGATTC---> GAT/CGGATTC