Let`s assume a guy has the correct fuel, timing,ect. Can you over squeeze an engine and actually hurt power?

Let`s say a guy in a HEMI has a small cam and 9 to 1 compression is more than enough. Assuming the guy has the correct fuel will he *always* make more power with 12 to 1? What about 14 1/2 to 1. is there a point where it might hurt power?

Thanks!