That wouldn't disprove evolution. You'd just say that men and dinosaurs must have lived together, and postulate a new common ancester farther back in time.
That isn't just talk, we've done this already many times, as we've found virtually modern-looking human skeletons dating farther and farther back in the timeline.
A discovery of two creatures in the same strata that were supposed to be separated in the evoulutionary timeline is often hailed as proof of evolution, rather than a debunking, much like any weather pattern, be it extra-dry, extra-wet, cold, hot, stormy, quiet, whatever, is a sure sign of global warming.
Of course, if evidence was found of humans and dinasaurs living at the same time, it is probably more likely evolutionists would simply deny the validity of the evidence, unless it is bones of a dead human inside the fossilized chest of a dinosaur -- because while evolutionists can easily re-write their mythology, it still is a pain in the butt to do so.
Is the discovery of the same building blocks used over and over proof of evolution, or proof of an intelligent designer? One thing is sure -- it's proof that God was not a software engineer...... (unnecessary programmer joke)