From Karban and Huntzinger’s How to Do Ecology: A Concise Handbook:

Unlike some other scientific disciplines, ecological principles are not universal. Finding a single counterexample will make us rethink our working hypothesis about the force of gravity. However, finding a single counterexample does not disprove our ideas about competition. Similarly, unlike other disciplines, ecological hypotheses are rarely mutually exclusive. Even if competition is found to be important, predation may also be important.