Negative testimony
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
Testimony not bearing directly upon the immediate fact or occurrence under consideration, bat evidencing facts from which it may be inferred that the act or fact in question could not possibly have happened. See Barclay v. Hartman.
2 Marv. (Del.) 351, 43 Atl. 174.