The CCTV recording would be direct conclusive evidence. In the absence of such evidence, testimony that can't be disproven in cross and casts reasonable doubt will work just fine.
Even with a CCTV recording, you can use testimony to cast the CCTV recording in a light favorable to either the prosecution or defense. The circumstances surrounding evidence are weighed in order to come to a verdict or judgement.
Court cases are not about "who has the most incontrovertible proof", they are about convincing a judge or jury of an idea in order to get a specific outcome. Do not underestimate testimony (or really, any evidence that you think is inferior)
