This movie has so many flaws... (spoilers!!)
1 - Why did the nurse give the contact information about her ex-Stasi "friend" to Martin Harris like that, out of the blue?
2 - How can you pretend for a long time to be a researcher with a guy (Prof. Bessler) who is among the best in the world in the field?! Moreover, Dr. Martin Harris surely appears only in those fake websites that his killer friends made up however he will not appear in any scientific publication whatsoever: I mean, the research is pissing off people that is ready to send kamikazes and they won't do a 5 minutes background check on a guy that is going to collaborate for months with them?!! And how can Martin Harris discuss about scientific matters with Prof. Bessler?!
3 - No way that an illegal immigrant is going to risk everything (and go back to Bosnia where they slaughtered her family--her own words) to save Martin Harris ass when he's kidnapped by the killers...
4 - worst killers EVER! A woman coming with a lousy taxi arrives and what happens? The killer is run over and thrown down the building along with his chief inside the van?! Wtf?!
5 - Why on earth didn't they kill Liam Neeson right away when he showed up without memory? The scene in the hospital was ridiculous, why breaking everyone's neck except Liam's one?! Why bothering poisoning him, just stub him/crack his neck as you did with any doctor/nurse in the neighborhood
6 - Why would the blonde try to deactivate the bomb?!? It's not that they didn't discover it
7 - Why did Liam Nesson became a good guy at the end?! Why!?!? It doesn't make sense in any way?!?
8 - So you placed a bomb that destroyed a building, confessed to be a killer, assassinated few people, destroyed half Berlin and guess what?! At the end of the day you can just walk away as if nothing happened.... wtf?!?
BONUS: Martin Harris (a killer with tons of risky information in his damaged head) goes nuts and literally nobody cares?! Nobody sent to check his status and see if he's leaking important info? For 4-5 days?!
BONUS 2: a professional killer that forgets his most important/vital suitcase at the airport. Seriously?