Blooper

After the electroshock baton is put in Katie's mouth, it is placed on her right leg and she is shocked again. The camera moves away and back again and the baton is now on her left leg; however, this was one continuous electroshock.

Ana's surname should be 'Patova' - note the feminine affix -a. This is because in Slavic languages, surnames ending in -ov or -ski are grammatically considered adjectives and must therefore match the gender of the bearer. While Slavic surnames tend to have proper gender forms ignored in Anglophone countries, mostly for practical reasons, Ana was born and raised in Bulgaria, and thus her surname would follow Slavic suit.

When Katy is electrocuting the guy, he is still conscious after he shouldn't have even been alive, much less conscious.

No explanation as to how they kidnapped Katie and got her to Bulgaria while keeping her hidden. However human trafficking happens all over the world in all manner of ways. This is a fact. Just because it's not shown how it was done here does not make it a plot hole. What is important is whether or not it's possible, and it is.