The problem of defining a proper heraldic depiction is evident in the example included in the link. Vertical and horizontal patterns are self-evident, chevrons are interesting, and diagonals are problematic. In the description / blazon of these patterns the primary tincture is placed in the heraldic upper right / dexter position. Sometimes that results in the bisection of the angle with the primary tincture (argent) as the first stripe on the top line as in this case - as it should be. However, there is another rule that needs to be applied additionally to bendy patterns, which is that the primary tincture should also occupy the first stripe of the insignia. In the example linked, the crescent-like slice at the lower left is blue, and that is wrong, when the blazon is bendy, argent et azure. And if that error is corrected, then the color scheme is reversed, violating the first rule. Either way something is wrong.
The problem is insoluble in the system being used to depict this heraldic pattern. The graphic system is incapable of satisfying the more general rule and the bendy specific rule at the same time. The problem is an inherent structural flaw that results from the generation of three stripes off the top line. The situation is corrected by the use of a structural pattern that takes four stripes off the top line and satisfies both rules. An example of which can be found in the tomb of Ottobuono Fieschi.
The problem is insoluble in the system being used to depict this heraldic pattern. The graphic system is incapable of satisfying the more general rule and the bendy specific rule at the same time. The problem is an inherent structural flaw that results from the generation of three stripes off the top line. The situation is corrected by the use of a structural pattern that takes four stripes off the top line and satisfies both rules. An example of which can be found in the tomb of Ottobuono Fieschi.