The 1-2-3-4-5 labeling is of smaller degree. The A-B-C is labeling is part of a lager degree.
Therefore, the A-B-C corrects a larger 1-2-3-4-5 not seen on the limited chart.


In the aforementioned Spanish website, the following is said in regards to a truncated fifth wave failure...


—After the “failure” has occurred, the price should go back the entire movement of the previous impulse pattern, that is, it should return to the origin of the pattern.

—If we are facing a failure pattern, the market should probably go back to the origin of wave 1.


Note the bold typefaced words. Exact science, is not exact science.

When a fifth wave failure occurs, it is a sign of weakness forewarning of a deeper than usual retrace in the opposite direction. On smaller degree waves this could more likely retrace the entire prior impulse, but perhaps less likely to do so on larger degree waves.