PSA tests aren’t wrong/misleading (unless there’s a lab error). Many people have simply misunderstood its purpose.
For initial diagnosis, a PSA test isn’t a “cancer test.” The PSA number itself is similar to a “check engine” light in your car; it indicates that something may be wrong, and further checks should be made “under the hood.” Might be as simple as a UTI; might be BPH; might be more serious. (Or the man might have engaged in an activity causing a temporary rise in PSA. Many things can affect PSA, which is why it’s important to be sure that your PSA is as accurate as possible.)
Just need to have further checks. No need to panic, or rush to a quick treatment decision, or get overly concerned. With early and annual screening, if there is an elevated PSA, other tests and numbers should also play a role in deciding on additional treatment.