It's neither a matter of 'definition' nor is it semantics. The British were engaged in a raid in southern Spain and the 'raiding' force defeated a French force of equal strength. The results were that the British were forced to withdraw as they were too weak to do much and had little support as to artillery and transport.
What has to be judged both practically and operationally is the results. Winning battles is a good thing-winning the campaign, as has already been explained, is much more important. Battles that have little or no result is the loss of personnel to no purpose.