The speed at which jutsu are performed has nothing to do with rank :|Ok lets assume your Dojutsu didn't work, he then used a quicker jutsu then a forbidden one, [Assuming quickest is E-Rank and Longest is S/Forbidden Rank.] His attack would have hit you before you were done your hand signs correct? [Not like this conversation matters as Kiwi is banned I just want to gain furter understanding of both perspectives. xP]
There are some S-rank jutsu that people can use without even performing more than 2 handseals while some E-rank jutsu take 3