Speakers adhere to linguistic norms in varying degree regardless of whether they speak the standard language. Occasionally, they seem to depart from normative pronunciations for reasons that have largely to do with ignorance rather than willful deviation.
An example of this state of affairs was recently furnished on NPR when one of the announcers used the non-normative––but currently widespread––stress in the adjective electoral, when he put the primary stress on the third syllable rather than the second. In all other respects, this announcer’s speech adhered to the current American English norm.
The question posed here is: how does one evaluate this departure from the traditional norm? The answer is: this is clearly the result of ignorance of the normative stress. This speaker most likely has never heard the correct stress in this word, and probably makes the same mistake in similar words, e. g. doctoral, mayoral, etc., with the same adjectival suffix.
A mistake of this kind can be called a “shibboleth” because it fits the definition of this term, i. e., “a sound or a word containing a sound whose proper articulation is difficult for and whose mispronunciation is regarded as reliably indicating or betraying a speaker who is not native or whose speech has been influenced by early acquaintance with another language” (Merriam-Webster Unabridged Online). Ultimately, it is an index of a lack of learning.