To answer your question, we need to decide if you are referring to the first or second battle at Bull Run. If the report was referring to the first battle, you probably wouldn’t be too worried. You most likely would report that this was a bump in the road. You would express a lot of optimism that things will be fine going forward. You might say the Union army underestimated how well the Confederate army was prepared. You might rationalize that since this was the first land battle, the South was really fired up for it. However, you would expect things to improve for the Union army very soon.
If this report was filed after the second battle at Bull Run, you would be much more concerned. After this battle, Washington, D.C. was in danger of being captured. The Confederate army was only 20 miles from the capital. You probably would report that the Union army wasn’t prepared, and by now, it should have been more prepared. You might say the leader of the Union army in the East wasn't very effective. You might even say the leader of this army should be replaced.
The report would look very different depending after which battle the report was filed.