I agree, Eric streaked prior to sanitizer application and the test seems to represent a condition that may be similar to actual conditions.
However, the test does not simulate actual conditions. The test was flawed the moment that the surface of the plate was allowed to remain at Star San pH during the incubation period. That's not what happens when one sanitizes with Star San due to the pH buffering effect of adding a much larger volume of liquid with a higher pH to the Star San sanitized vessel.
The other plates tested the sanitizer's ability to kill viable cells because the sanitizers have no residual effect. Alcohol ceases to be effective the moment that it flashes off, and so does iodophor when the iodine sublimates into iodine gas. Those two plates tested the sanitizers' ability to truly kill vegetative cells because nothing was left to hinder the growth of cells after the sanitizers left the surface as gases.
One of the terminology problems that we routinely see in home brewing is the intermixing of the terms sanitation and sterilization. The goal of a sanitizer is not kill every vegetative cell. The goal of a sanitizer is to kill most of the vegetative cells. True sterilization kills 100% of the vegetative cells and 100% of the spores that can germinate into vegetative cells. Boiling is in between sanitizing and sterilizing in that it kills 100% of vegetative cells, but does not kill spores.
Let's look at a commercial sanitizer for one's home; namely, Lysol. It's maker claims that Lysol kills 99.9% of viable cells. It only takes one viable cell to produce a colony-forming unit (CFU), which is why CFUs are known as pure cultures. That claim means that we are almost guaranteed to have one CFU form if the sample that we use to streak a plate contains at least 1,000 viable vegetative cells. A CFU contains a large number of cells. A Saccharomyces cell is 5 to 10 µm in diameter, which means yeast cells are at least 1/5th of the smallest size that is visible to the naked eye.
While yeast cells will not replicate very well at Star San solution pH, it does not mean that they are dead. A yeast culture can contain a bacteria load. Yet, the bacteria load will not rear its ugly head as long as the pH remains below 4.6, which is the pH at which many bacteria species stop replicating (one of the reasons why we do not want to rinse yeast with and store it under boiled water is because doing so raises the pH of the culture). Yeast is also susceptible to pH-based growth limiting. It's just that domesticated brewer's yeast can withstand a lower pH than most bacteria species. Anyone who has made a batch of mead where the pH dropped into the low threes has noticed sluggish to non-existent fermentation. The yeast cells are not dead. All one needs to is to buffer the pH of the mead back up to over 3.5 or so, and the fermentation will usually restart.
I shot the photo shown below. It is a batch of Star San that I made with water that contains 130ppm as CaCO
3 alkalinity. Yet, the pH is way below the pH at which most brewer's yeast will replicate or even function, and the pH of Star San that is made with distilled water is even lower (< 2.0).