For sure. But my take is that OP messed up the vetting, now time has passed since the honeymoon phase, things have gone downhill, and he's had to resort to unsavory methods to confirm his questions about his partner's history and relationship value.There is a distinct difference between vetting and snooping around someone’s privacy for reasons to disqualify them. OP set out to manufacture evidence to get rid of old girl. This is problematic because all humans are flawed. You get maximum 80% of what you want out of a person. If you go looking for flaws, you will always find them.
You can still look for flaws critically and take time and effort to pick the 'least flawed' option. OP likely messed up by not doing more of this at the onset of the relationship. But that's a common mistake a ton of guys, my younger self included make: you get so enamored with the new puss that you overlook a bunch of things; next thing you know you're one year into a relationship with the wrong person.