We Never Know
No Slack
If you reread that he did not imply that condoms were 100% effective. He gave one case where a pregnancy was avoided. That does not say or imply that they will work 100% of the time. It is rather hard to get a per use efficiency since most of the studies I have seen cover how likely a pregnancy is in a year without saying how often the people had sex.
Focus on my point... 'However condoms do cut down the chances of pregnancy so in turn cut down abortions."