IMHO, a school is only as good as the instructor. And the instructor is only as good as the teachings he/she gives the students.
I truly believe if there WAS one martial art that was the “best” (which there IS NOT), it would be very possible to fuck it up due to a teachers incomplete knowledge or lack of teaching skills.
I would say to just go with your gut. The gut is never wrong…but it takes courage to listen to it. Don’t rationalize…just go with your gut instinct.
Ask yourself if this particular school is good. Is it what you want? What is your first answer…the most immediate answer that usually appears as a shuddering in the stomach is usually a “no”. If you don’t get that feeling, then do what you think is right…