What is the standard for determining whether statements made during and furtherance of a conspiracy were clearly erroneous?

The clearly erroneous standard appears appropriate because the questions whether the statements were made during and in furtherance of the conspiracy are threshold findings of fact. Thus, the trial judge's conclusion must be affirmed unless it is clearly erroneous. See United States v. McConney, 728 F.2d 1195 (9th Cir.) (en banc), cert. denied, --- U.S. ----, 105 S.Ct. 101, 83 L.Ed.2d 46 (1984). A "definite and firm conviction of mistake" does not arise from review of this record.