I agree with Jessie -- it was best keep the rehearsal moving. Your ASM did what they should have -- the director needs to refocus their anger onto the actor that forgot their line -- what happened that the actor forgot? Were they screwing around, or was their something actually wrong that caused them to go up during a tech rehearsal?
Put yourself in the actor's place, if only for a second. Everybody should realize how much tech can screw with actors. Basically, they're taking 4-6 weeks (or more! of extremely hard work -- and then all of a sudden, they get bright lights thrown in their faces, heavy and possibly awkward costumes and shoes to wear, platforms and stairs where there were none before, new and different props to handle and figure out, and all the while designers and others are talking in the house, the crew is stepping on their toes for scene changes, they can't see anything 5 feet in front of them past the edge of the stage....of COURSE they're going to get thrown off the first couple times out of the box. If they lose a line, its not because they were goofing off or not paying attention (hopefully, anyway!), but more likely it's because they were always used to looking at a specific chip in the paint on the wall when they said the line before and now they have to get used to looking out at black expanse.
Granted -- a professional/seasoned/good/confident/etc. actor will be able to make this transition from rehearsal room to stage smoothly and seamlessly and nobody will be the wiser what they are actually struggling with. But a less experienced actor will have more trouble, and (at least IMO) we as management need to go by the idea that our job is to do everything within our jurisdiction and control to make the show run as smoothly as possible. If this means a little TLC to the actors at first tech, so be it. Yes, it's "our" time. I always tell my actors and dancers that they have had weeks and possibly even months to prepare, the designers and crew get just three days to a week to figure everything out. They need to know their part as well as possible so that they are prepared to deal with all of these additional elements. But even though its our time, we still need the actors to do the show! It is important that they are comfortable in their new surroundings and with how the show is going to run.
(Just think of an animal being transplanted from the Sahara into a commercial zoo in the United States....of course it will take some getting used to!)