The key to what you’re asking is your statement:

> The ball was not touched by the person who hit the hand of the QB

If you frame that in the context of the [eligible receivers rule]( http://static.nfl.com/static/content/public/image/rulebook/pdfs/11_Rule8_ForwardPass_BackPass_Fumble.pdf) you'll see…

> ELIGIBLE RECEIVERS
> 
>  Article 5 Eligible Receivers.
> 
>  The following players are eligible to catch a forward pass that is
> thrown from behind the line of scrimmage.   (a) Defensive players.
> 
>  (b) Offensive players who are on either end of the line, provided
> they either have the numbers of eligible players (1-49 and 80-89) or
> have legally reported to play a position on the end of the line. See
> 5-1-2.   (c) Offensive players who are legally at least one yard
> behind the line at the snap, provided they either have the numbers of
> eligible players (1-49 and 80-89) or have legally reported to play a
> position in the backfield.
> 
>  (d) All other offensive players after the ball has been touched by
> any defensive player or any eligible offensive player.

The key to your question is 5d.  Since the defender **did not** touch the ball, the O-lineman is not eligible.