dissenting.

A defendant’s excuse for not responding timely to a validly served complaint must be established by proof, not by unsworn argument. Bil-Jax Inc. v. Williamson, 497 So.2d 1350 (Fla. 4th DCA 1986); Gibraltar Service Corp. v. Lone and Associates Inc., 488 So.2d 582 (Fla. 4th DCA 1986); C.E. Peters Landclearing Inc. v. Gossington, 487 So.2d 319 (Fla. 4th DCA), rev. denied, 496 So.2d 142 (Fla. 1986); Hall v. Byington, 421 So.2d 817 (Fla. 4th DCA *10331982); and Yu v. Weaver, 364 So.2d 539 (Fla. 4th DCA 1978). The usual form of this proof is an affidavit, but testimony at the hearing will also do.

Here, there was neither. I reach this conclusion because appellant says there was no testimony at the hearing on appel-lee’s motion to vacate the default final judgment, and the motion was unsworn. Appellee did not file any brief in this appeal, a failure which I take to be a concession of the accuracy of appellant’s account of the proceedings below.

A reversar is unavoidable.

AFFIRMED.

specially concurring.

I concur specially to comment on the dissent. I have never before seen nor heard that the failure to file a brief might be a confession of error. Were this so, every answer brief unaccompanied by a reply brief would result in invariable af-firmance. Surely the appellant must demonstrate error.