Brentford boss Frank wants apology after penalty controversy
Frank's team were beaten at St James' Park after Callum Wilson converted a second-half penalty awarded for a foul by Brentford goalkeeper Mark Flekken on Anthony Gordon.
The penalty was one of two given by referee Craig Pawson, although the second was rescinded after he was advised to review it.
Frank was convinced Newcastle should not have had either penalty and he believes Webb should be in touch to say sorry.
"It's so rare that I complain about it because it's human beings who make mistakes and we all make mistakes so that happens. But it's extra frustrating when we do so many things right and lose because of that," he said.
"We just got told four weeks ago when Kevin Schade went through against Tottenham, where the keeper took him out, that no, he pulled out before, so it can't be a penalty. Mark pulled out before, now a penalty.
"It's not the ref who has given it but the linesman, and he needs to be absolutely bang-on, 100 percent sure if you want to decide an even game between two teams that gave each other a fantastic game, in fact.
"That means that VAR have checked, but can't do anything because it's not a clear and obvious failure. I'm pretty sure that Howard Webb will come back to us and say 'Sorry, we made a mistake'."