The TVG commentators(who were surprised at the ruling) were asking themselves if "herding" is allowed in Pennsylvania. I found this on the PA Website:
CHAPTER 163. RULES OF RACING
163.234. Crossing and weaving.
During the running of a race, when clear, a horse may be taken to another part of the course but a horse may not cross or weave in front of other horses in such a way that would impede them or constitute or cause interference or intimidation.
https://www.pacode.com/secure/data/0.../s163.234.html
Not sure what the TVG commentators were questioning. This seems to be the same rule in every jurisdiction? No?