The Buddha obviously did not endorse abortion, placing strict prohibitions upon monks arranging or recommending abortion. Yet the Buddha obviously did not expect all people to follow his path.
For those that believed they made a mistake in life, the Buddha was always ready to forgive (end of DN 2 for example). Buddha practises forgiveness rather than terrorises people caught up in difficult life situations.
As for kamma (action), the effects (vipaka) generally follow on the intention. Thus, it is said: “kamma is intention” (AN 6.63) 