The police force of Hungary is not the Hungarian National Police just simply Police abbreviated as ORFK not HNP. Clearly the script writers never researched well.
The plot is far-fetched and not what a FBI International Operations team should investigate. No American citizens were involved. More appropriate would be requesting Europol's or other European police forces for assistance and impartiality.
Europol Agent Megan 'Smitty' Garretson raised a firearm to arrest Ben's partner. In reality, Europol officers do not carry firearms.