If it makes you feel better, most people have had trouble with this fellow for a few patches. It actually worked best when it was introduced if I remember correctly.
The last time I did it, one of the checks to lift the fallen beam didn't actually remove his scripted prone state. Attacking the beam directly, and using the help action is how I think I did it.
Talking to him directly does have the added benefit of giving you control of his actions, which is useful.
