The first fugitive caught by Brian is said to be "#4" on the FBI's Ten Most Wanted list. Actually, fugitives on the real Ten Most Wanted list are not ranked, nor is there a "#11" that is elevated to the top ten when one of them is caught. When a vacancy is created in the list (due to a fugitive being arrested, dying, or the charges being dropped), FBI Headquarters instructs its various field offices to submit new candidates. The selection process is extremely slow and can take months (which has sometimes led to an already-caught or dead fugitive remaining on the list for nearly a year).
Back in _"Limitless" (2015) {Badge! Gun! (#1.2)}_, the cliffhanger had Brian hire his father as his lawyer so he could share his NZT secret with him, but a warning from Sen. Morra stopped him right on the verge of speaking. It left audiences waiting to see how Brian wriggled through that tight situation, but what happened next never came about. Now here's Brian trying to figure out why his up-till-now loving father won't speak to him anymore. It's the same issue as earlier, but no reference is made to when Brian hired his dad as his lawyer, as if the incident never took place.
Agent Harris tells Brian that they can't travel to Tanzania, as a visa is required. While it is correct that US citizens require a visa to visit Tanzania, it can be purchased upon arrival, and thus the requirement would not hinder their ability to travel there.