LOS ANGELES (AP) _ Jurors who spent 10 months hearing evidence in the ''Twilight Zone'' manslaughter trial said Friday they took only one vote in finding the five defendants innocent and suggested the filmmakers never should have been put on trial.

The seven men and five women, some of who hugged and kissed the defendants and their lawyers after the verdicts were returned, said they believed the defense on a key theory of what caused the helicopter crash that killed actor Vic Morrow and two child actors in July 1982.

Jurors Lauretta Hudson expressed outrage that director John Landis and his codefendants were singled out for prosecution when others who were on the movie set were not indicted.

''We felt that if the five were guilty, so were the firemen and the stuntmen,'' she said. ''They were there. If they saw something wrong, they should have said so.''

The jurors returned verdicts of acquittal Friday on all involuntary manslaughter charges against Landis, associate producer George Folsey Jr., production manager Dan Allingham, special effects coordinator Paul Stewart and helicopter pilot Dorcey Wingo.

''It is our current state of mind that this was all an unforeseeable accident, and you don't prosecute people for unforeseeable accidents,'' said Lois Rogers, who led the jury's deliberations.

She said the jurors had no disputes from the outset of their deliberations May 18, and took only one vote. She said they asked to have testimony re-read from the trial's earliest witnesses because ''most of us were first-time jurors and we didn't take many notes back then.''

Mrs. Rogers jurors had doubts about the truthfulness of the trial's first witness, production secretary Donna Schuman, who became a keystone of the prosecution case.

''There was a lot of her testimony that was not credible,'' Mrs. Rogers said.

Mrs. Schuman, who was attacked as a liar by the defense, testified that Landis and Folsey speculated before ''Twilight Zone: The Movie'' was filmed that they would wind up in jail for using children illegally on a nighttime set with a helicopter and explosives.

The defense claimed she made up statements she attributed to the two defendants.

The explosions were part of a Vietnam War scene involving Morrow and the two child actors, all of whom were killed when the helicopter crashed on top of them.

The jurors indicated that they have few clues even now as to what caused the crash, and suggested the prosecution should have presented more evidence on that point.

''There was not enough evidence brought out that proved why the accident happened,'' said Mrs. Hudson. ''A straw through a potato meant nothing.''

She referred to a demonstration offered by prosecutor Lea Purwin D'Agostino during her closing argument to illustrate how a piece of bamboo shot into the air during a special effects explosion could have penetrated the helicopter's rear rotor blade.

''We were more impressed with delamination: that was proven to us,'' Mrs. Hudson said of the defense theory that an unexpected heat reaction from the blasts caused the skin of the tail rotor to peel away, or delaminate, causing the crash.