No one here could possibly answer based on this question. Can you provide the original inspection pictures and inspection report? It is important to note that mold spores are present almost everywhere. It is when they have a medium to grow that they can become a problem. What they “look” like “before” there is a problem and what you may think you see “after” the problem arises because of changes in the environment after the time of the inspection may be subject to interpretation. Without knowing the certifications of the inspector, he should not make mold “speculation” comments at all, as this is a specialised area which requires training.
It is an important to note that an inspection is a snapshot in time and is not intended to predict future conditions. What may look like dirt , soot, scuff marks from plastic, spilled cleaning products, baby powder, oregano, etc. (you get the idea) on the day of the inspection cannot be predicted to be a future mold outbreak in a home you purchased “recently”. It is not a job for an inspector to speculate what these marks or smudges could be. there is an expense associated with sampling and testing these areas which you now say were “very visible” ( I charge a base of $195 for the first two samples and $60 for each additional sample, plus any associated express costs for quick lab turnaround.)
If they did appear to me to be a mold-like substance, I would mention them to you and ask if you wanted the additional testing. Beyond that, It is not required nor prudent to raise the specter of possible mold contamination where there is none.
Thanks and I hope this helped