concurring specially.
I concur with the majority’s judgment, but I would note that the reason the trial court could not permit the late filing of the expert affidavit pursuant to the exception provided in OCGA § 9-11-9.1 (e) is not because the original insufficient affidavit had been filed, as opposed to mistakenly not filed. Instead, it was because the defendant could not show, as required by that subsection of the statute, that the affidavit was available prior to the filing of the complaint. It was not merely due to an inadvertent mistake that an unsigned copy of the affidavit was filed with the counterclaim. Instead, the defendant admitted in his brief to the trial court that the attorney for whom the original affidavit had been drafted determined prior to the filing of the counterclaim that he was disqualified from offering an opinion in the case due to a conflict of interest. I do not want it to appear from this opinion that a claimant would necessarily be precluded from filing an amendment pursuant to OCGA § 9-11-9.1 (e) if, by inadvertent mistake, an unsigned copy of an affidavit was filed that was otherwise available to a claimant at the time of filing the malpractice claim.
OCGA § 9-11-9.1 (e) expressly states that the provisions of OCGA § 9-11-15, permitting amendments to complaints, cannot be used to circumvent the requirement of timely filing an expert affidavit with a complaint. By the same reasoning, I agree that the provisions of OCGA § 9-11-13, permitting amendment to pleadings to add a counterclaim, cannot be used to circumvent the requirement of timely filing an affidavit.
*522Beltran & Coffey, Frank J. Beltran, Simone R. Siex, Ralph Per-ales, for appellee.