(1) I have never been tricked while I was shopping at ABC. (mixed tenses, okay)

(2) I have been tricked a few times while I was shopping at ABC. (a tense mismatch, wrong)

(3) I was tricked a few times while I was shopping at ABC. (a tense agreement, okay)

(4) Have you ever seen a tornado while you were driving to work? (mixed tenses, okay)

(5) Have you ever seen a tornado while you have been driving to work? (sounds awkward)

My friends and I have spent a lot of time discussing whether or not "ever" and "never" allow mixed tenses in the same sentence.

Most of us think "never" and "ever" allow a tense shift because these words indicate an event happening in the past, leading up to the present. So, it is okay to have mixed tenses (present perfect and simple past) in (1) and (4). (3) is certainly correct because the simple past is used in the whole sentence. However, the mismatched tenses in (2) make it grammatically wrong and the present perfect in the dependent clause of (5) "while I have been..." makes it sound odd.