I was referring to the fact that one side turned it's tail and fled relatively . The First Battle of Bull Run would not be considered epic, as you mentioned in your post, and neither would said scene from LBT5, despite it being the closest candidate, IMO.
On a historical side-note, I think it is kind of a misrepresentation of the battle of Bull Run that almost since the day it was fought it has been known almost only for the route of the federal army and the firm stand of the brigade of Jackson who got his nickname "stonewall" in that battle. Some also remember the disorganization of the federal army (a regiment leaving on the eve of the battle because their three month term had run out and other outfits were delayed because soldiers started picking berries from bushes along the side of the road).
What is often overlooked is that the federals came pretty close to a success. Both sides were rather green, but considering their green state the battle was more than the "brawl" as which it is often depicted
The federal retreat (it began as a retreat before it degenerated into a rout) started only between 3 and 4 pm, that is after something between five and six hours of intense fighting after a long flanking march.
Part of the federals defeat was caused by "bad luck" (the confusion of the blue clad 33rd Virginia regiment for a federal unit and the loss of a federal battery as a consequence) and the degeneration of the retreat into a rout was partly because of the tricky escape route (across the narrow stone bridge) that was partly blocked by the battlefield tourists from Washington.
In spite of all this some units that had not seen action in the battle itself did not join the rout but stayed and (even without another battle resulting from it) probably played an important role in the lack of attempts on the part of the southerners (who were almost as disorganized by their victory as the northerners were by their defeat) to pursue the federals.
The battle of Bull Run was not a mere running and screaming on the part of one side at the first sight of the enemy and seriously it did not have much in common with the LBT dinosaurs running from swarms of insects in LBT 5.