After Grant Holt's 16th goal of the season had equalised Chris Brown's opener for North End, the Canaries had a great chance to secure victory when they were awarded a spot-kick on 72 minutes after Darren Carter handled in the box.
But Hoolahan's chipped penalty, which drew claims of disrespect from Preston boss Phil Brown, was easily saved by Lilywhites goalkeeper Iain Turner.
Lambert said: "When penalties go in they look good however they are taken, and when they don't go in it is obviously a missed opportunity.
"Basically whilst Wes felt confident to take the penalty the way he did, he certainly wasn't being disrespectful to their keeper. He didn't have to hold his hands up and say anything after the game - 26,000 people saw what happened.
"I don't tell players how they should take penalties but I don't think he'll be taking one again like that while I am manager. I think it's affected his confidence after that but I'm not going to sit here and criticise Wes. He has been excellent for me in the 18 months and has done lots of good things, helping us to pick up a lot of points."
Source: PA
Source: PA