concurring specially. I concur in the judgment of affirmance solely on the ground that the act of plaintiffs helper in operating the automobile and backing it into plaintiff was the sole proximate cause of the plaintiffs injury. I cannot agree with some of the reasoning of the remainder of the opinion, particularly the ruling that "with respect to the allegation of the unsafe loading area, this was pierced by the affidavit of the expert, to the effect that the loading dock was constructed in accordance with the general usages of those engaged in. that business.” While I can see that such evidence is admissible, as it is "competent to prove that the same thing was done by others in the same situation who were, presumably, ordinarily prudent men” (Arrington Bros. & Co. v. Fleming, 117 Ga. 449, 451 (43 SE. 691, 97 ASR 169)), yet, in order to pierce pleadings on motion for summary judgment the evidence must demand the finding required. Evidence as to what the custom of other men may happen to be does not demand a finding that one who follows that custom is not guilty of negligence. It is for the jury to find whether the others were ordinarily prudent men. " 'An ordinary custom, while relevant and admissible in evidence on the issue of negligence, is not conclusive, especially where the custom is clearly a careless or dangerous one.’ 38 AmJur 679, 680, Negligence, § 34.” Shirley v. Woods, 98 Ga. App. 111, 115 (105 SE2d 399). " 'The practice of others engaged in similar business is not the standard by which to measure the care required of one bottling highly-charged beverages for the trade.’ Grant v. Graham Chero-Cola Bottling Co., 176 N. C. 256 (97 SE 27, 4 ALR 1090).” Georgia-Alabama Coca-Cola Bottling Co. v. White, 55 Ga. App. 706, *282713 (191 SE 265). "What usually is done may be evidence of what ought to be done, but what ought to be done is fixed by a standard of reasonable prudence, whether it usually is complied with or not.” Texas & P. R. Co. v. Behymer, 189 U. S. 468, 470 (23 SC 622, 47 LE 905), cited with approval in Dawkins v. Jones, 119 Ga. App. 796, 798 (168 SE2d 881).