Revealing mistake: When Jensen is investigating the missing 4 million dollars from the account, we see the screen on his laptop. Among other things, it shows a picture of Fadhil's passport, which looks like it has a watermark on it, readable as http://slawek.com. Indeed, going to http://www.worldpassports.org/americas/pages/bolivia.htm you will find the passport pictured there. (01:01:35)
Other mistake: During the heist of the armoured car, The Losers detonate the explosive device on one of the black SUV's and it then blows up and rises up vertically. The problem with this is the explosive device was attached to the side of the SUV, and it really should have blown it sideways and up, not just vertical.
Pooch: Oh my God I'm the Black Macgyver. Blagyver.