Would everyone agree that maybe my best bet would be to wait until the
tank fills with 1500 gallons of water over 3 weeks following the
pumping/inspection of the tank in order to see if the water level
reaches the pipe, as it should if the leak has been fixed?

Can anyone think of anything else bad that might cause the water level
to be low that could be missed on an internal inspection of the tank?
Im assuming that the person who inspected it is honest and there were
no other cracks. Can cracks in a concrete tank be accidentally missed
with internal inspection? I'm basically trying to decide if I should
hire someone else to inspect it.

Points about this not mattering as long as the septic tank is not near
well water (no well water, city water) are well taken. I also realize
that an overflowing tank is more of a problem, but the tank is right
next to the house and I don't want this stuff leeching into the
basement, etc.

Thanks