i was more looking for an answer to the question about why would the caa compare both log books?
No. That was not your question; and that issue did not even arise until subsequently mentioned by AerBabe.
I don't know if you are consciously or subconsciously inventing
ex post facto justifications for your posts, but it is only making things worse.
Your question contemplated what can only be defined as deliberate fraud, and that it why it upset people. Aviation is heavily regulated, but (by and large) the authorities allow pilots considerable latitude, on the assumption that they are honourable and trustworthy people. Usually, that assumption is fully justified.
I sincerely hope that you have learned a valuable lesson and will decide not to pursue a "who would know?" attitude in your flying career.