The dinosaur experiment
Some people have been claiming the evolution is falsifiable. As an example of a way to attempt to disprove evolution by experiment, they give 'the dinosaur experiment.' In this experiment, researchers attempt to use genetic engineering and selection over many decades to breed dinosaurs from crocodiles. There are many reasons why this is not a valid test of the theory of evolution.
First of all, you cannot prove the evolution is false using this experiment, only that it is true. Suppose after a million years there was no clear 'progress.' The researchers would just say you need another million years to see progress. No matter how little progress was made, there would never come a time when you could halt the experiment and say evolution had been disproved.
The researchers could also argue that the conditions were not right and that a much larger population of crocodiles was needed, as well as more time.
The current theory predicts millions of years and beneficial mutations. Not decades.
Including genetic engineering would make it impossible to make any conclusions about evolution - it would actually point towards intelligent design.
Even if an hypothesis is falsifiable, if you fail to carry out the experiment you are stuck with an untested hypothesis, not a broadly accepted theory. Continuing to make observations that concur with the original observations on which the hypothesis was made proves nothing, as far as science is concerned.