The Supreme Court is considering an unprecedented decision by a lower tribunal that allowed a so-called "in-plant strike" to trigger the discharge of all unionized employes although there was no official finding that all or even a substantial number of them had engaged in disruptive actions.

A divided 5th U.S. Circuit Court of Appeals handed down the decision last August in a case involving a Johns-Manville Products Corp. plant in New Orleans and 107 production and maintenance employes - members of the Oil, Chemical and Atomic Workers International Union, AFL-CIO

The gist of what the government calls "unusual factual circumstances" was this.

The plant makes paper used in asphalt roofing. Both the paper and the production machinery can be damaged easily, either accidentally or deliberately. A saboteur can act surreptitiously with probably a small likelihood of detection.

After contract negotiations began in September 1973, the normal weekly average of paper breaks increased from a range of 3 to 8 to a range of 15 to 20.

Attributing the increase ot sabotage, the company initially locked out union employes and resumed partial operation with temporary replacements and with Johns-Manville employes brought in from other plants.

Finally, in March 1974, when bargaining was still at an impasse, the company began a three-month process of hiring permanent replacements for the locked-out union members without notifying the union.

The union complained to the National Labor Relations Board. An NLRB administrative law judge concluded that the reasonable inference to draw was not that the workers were responsible for the paper breaks, but that one or two dissidents had caused them.

His facts indicated that the company had less than one excess paper break per shift in the period August through October 1973. The record also showed that breaks occurred with unusual frequency in January, May and July of 1973 - months before negotiations begin.

The board ruled 2 to one that "a legitimate and substantial business purpose without antiunion motivation underlay the walkout and the use of temporary replacements. But it ruled 3 to 0 that the hiring of permanent replacements violated the National Labor Relations Act.

Even if all the disruption were deliberate, "a single individual could have done it," the board said. The board ordered the company to offer to reinstate the union members, compensate them for lost earnings, and bargain with the union.

The appeals court voted 2 to 1 not to enforce the order. While claiming to adopt the board's factual findings, the majority, in an opinion by Judge Peter Fay held that, "as a matter of law, the employes were involved in what amounted to an in-plant strike." The lock-out and hiring of permanent replacements consequently "were not violate" of the labor law, he said.

In the dissenting opinion, Judge John Wisdon termed the ruling "both factually and legally erroneous," partly because "the facts do not show a strike by anyone."

Instead, the record contains "substantial evidence" to support the board's conclusion "that the company indentified no workers as actually connected to any misconduct justifying replacement or dismissal," he said.

The majority's holding that, as a matter of law, a strike had occurred was both "unprecedented" and unsupported either by prior decisions or by considerations of labor policy, Wisdon said.

"Both law and policy compel the conclusion reached by the board that action may not be taken against in-plant strikers until the participating workers are identified," he added.

Agreeing with Wisdom in a brief filed in the Supreme Court, Solicitor General Wade McCree said that the ruling "is contrary to decisions of this court and of the courts of appeals, which have uniformly held that only those employes who are shown to have been guilty of unlawful or unprotected activities may be discharged."