Also, remember, the decision is COMPLETELY up to you, do what you want, you never know what the consequences will be necessarily, if any, and, it is all about you doing the job how YOU see fit. There are 20 endings and all to varying degrees just depends on some slight actions here or there to give you the differing results. I pretty much ignored some of the rules and let people in sometimes even if they were invalid (quite often really, I found reason to let them in, and usually with no bad consequences) and denied people even when valid, depending (though that less often,)
One example I like is when someone's name is 1 letter off, from a different country, and you should technically decline them, but, really, the difference between an A and an E on the passport or whatever between 2 different countries, where it could practically be interchangable usage of letters? I let them go in!
I hope your real life job doesn't involve border security. ;)
I did the opposite - whenever a discrepancy appeared I did the check, and if given the option to arrest I took it every time. Excessive? Probably. Profitable? Definitely.
Unless of course they gave me a bribe... ;)