Bob, the prosecution built it's case around the LIE that these two BP agents were rogue cops and deliberately and willfully broke the law in the pursuit of an illegal alien. DHS was the investigating authority for this entire case, and their findings were used against the BP agents in court - as was their testimony. Conversely, testimony was NOT ALLLOWED that would expose the "illegal alien" as a criminal drug smuggler. Nor was testimony allowed that showed the BP agents as stellar cops (previous citations and awards and such)
As well - and I can't believe I have to point this out to you - the fact that DHS lied to Congress indicates a large-scale cover-up. DHS did not want the Congressmen to go any further in their questioning of the case. In fact, many Congressmen and Senators did just that - they stopped looking into it. That was exactly the purpose of the LIES.
Ig the prosecutor told this to the jury, wouldn't he have to back that up with some evidence? If so, what was revealed during the trial?
You seem like you've been keeping a close eye on this event, so I assume you know what went on during the trial.