I tend to disagree.. I have done some things which I thought was experimenting with but did not come up with any clear conclusion after the experiment and analysis. On rewriting the thesis it turned out there were a lot more implicit assumptions inside the hypothesis that I was not aware of. I think it was a badly designed experiment and it was rather unproductive in retrospective analysis. I suppose one could argue that it brought to light the implicit assumptions and that was a useful result. Somehow(not sure how or why) I find that a low standard to consider something an experiment.

Systems built without requirements cannot fail; they merely offer surprises — usually unpleasant!

— Robert Morris, quoted in Brian Snow's "We Need Assurance!"

Experiments can fail if they are executed or planned improperly. If both the control and the experimental group are given sugar pills, for example, or the equipment fails in a shower of sparks, the experiment has provided no evidence by which one can update. It is a small quibble, and probably not what the quote meant to illustrate (I'm guessing that the experiment provided evidence which downgraded the probability of the hypothesis), but something to note nonetheless: experiments are not magic knowledge-providers.

An experiment is supposed to teach you the truth. If you run the experiment badly and, say, get a false positive, then the experiment failed.