Among the violinists was the composer Ludwig Spohr (1784-1859), who was astounded by Beethoven's conducting style, noting how he used "all manner of singular bodily movements. As a sforzando occurred, he tore his arms, previously crossed upon his breast, with great vehemence asunder. At piano he crouched down lower and lower to show the degree of softness. If a crescendo entered he gradually rose again and at a forte jumped into the air."
...From the website of the Northwest Sinfonietta. I can only imagine Beethoven jumping up and down, as enthusiastic as he could be -- but also as unpracticed and unstudied as an overenthusiastic college freshman (or perhaps a certain wascally wabbit? Bonus points: What is the song played by Bugs on the Sousaphone? Answer here). Beethoven was no "conductor" in the overly-qualified sense we are familiar with today, but he was a consummate musician. If the orchestras of the early 1800s are anything like those of today, I imagine that his prestige as preeminent composer of the half-century made the orchestra at this particular charity concert as attentive as could be. And the audience surely was drawn tremendously into the performance.
For more information on Symphony No.7, by the way, check out this NPR story.