Calling something a concomitant in a rhetorical expression does not always mean that the intended trait follows with certainty for every individual. A dog may bark little for many reasons, yet conventional speech can make this a sign of hospitality.
Likewise, a camel calf might be thin because it is ill, not because the owner gives away its milk. Kināyah selects a familiar relation to communicate an intended quality; it does not deny every other possible physical cause.
This distinction keeps rhetorical conventional inference separate from strict logical entailment.