Re: Fatal Flaw?
To answer the original question - don't explain it to the viewer.
SHOW it to them.
Just have someone try to send the data the sensible way first.
And then we see him get killed.
Our hero has the memory stick of what the guy tried to send, so it's up to him now.
And he's not going to make the same mistake we just saw someone get killed making.
It would also beef up the stakes by making him more of an 'everyday Joe'. He doesn't really understand the technicalities of what is on the stick or why he's being hunted.
And if his own personal stuff was on the stick that the bad guys (erroneously) recovered then now he and his family are at risk.
I vote for 'Let someone try the obvious way and get killed'.