Angler - Welcome to the forum!
I agree with Scott....often the BU will have a better angle to see these plays than the PU coming out from behind the plate. As PU I have been burned on this a few times with sinking line drives that were either caught or short hopped right in front of the infielder. If you are in a straight line with the fielder, it's almost impossible to see clearly.
On these plays as PU, I will hesitate a split second if I think the ball was caught and look at my partner for help. Hopefully, s/he is giving me some type of indication that the ball was either caught or short hopped (I know, more unauthorized signals
). You can also try to watch the fielder and let her tell you what happened. If she comes up throwing, the ball probably wasn't caught.