As you say, bees can travel quite a distance to collect nectar, so it is close to impossible to be sure they don’t end up with nectar that has some sort of contaminant. This is the same argument against the veracity of honey labeled 100% pure avocado or buckwheat. It is a highly suspicious claim. But even if true, it is a pointless claim in my mind. Most countries that set standards for specifying a specific source plant of honey require at least 50% of the nectar from the specific varietal in the overall content of the honey. Why? Because this is usually enough to provide the unique sensory characteristics of a particular plant. In my mind, this is somewhat arbitrary, because a strongly flavored honey of a particular type of flower may not require 50%. Dandelion honey is a good example. It is so strong, that even 30% is usually enough to provide the Dandelion aroma and taste. Whereas a plant that produces a mild honey, such as Acacia, may need 80% or even 90% content to be true to its characteristics.
Aid climbs are graded A0 to A5 depending on the reliability of the gear placements and the consequences of a fall. New routes climbed today are often given a “New Wave” grade using the original symbols but with new definitions. Depending on the area in question, the letter “A” may mean that the use of pitons (or other gear that requires the use of a hammer) is needed to ascend the route. The letter “C” explicitly indicates that the route can be climbed clean ( clean climbing ) without the use of a hammer. It is considered poor form to use hammered aid where clean aid will suffice. Furthermore, the clean equipment can be employed more rapidly and efficiently than hammered gear, so many climbers prefer it where possible.