It depends on your church structure but generally, whatever happens during the service is his responsibiltity.
I wouldn't want our senior pastor involved directly in technical decisions. But we have an assistant pastor that generally sits in on those decisions. Not having an assistant pastor, a trustee or someone from the financial team should be on board.
I would think the pastor would want to sign off on high level stage designs, but not involved in the minutia.
If you think your pastor is trying to insulate himself from this so that if it fails, someone else has to take the fall, then you have an entirely different problem.
But it could be that your pastor is already full up with all his other duties and he feels that he's showing you respect by delegating this and trusting your judgement.
Joel Osborn Milton SDB Church
"...if we are to glorify God fully, we must engage our mind in knowing him truly and our hearts in loving him duly." - John Piper, Think