Yes, I believe abortion is wrong. But murder is also wrong. Two wrongs don't make a right. And a wrong done for the right reasons is still wrong.
How should this have been handled? Since elective abortion is murder, the laws should reflect such and those who do elective abortions under such law should be found by the courts to be guilty of murder. (No, the law should not be retroactive, as no laws should be.) The law should then act and serve justice. If a murder is, for some reason, not legally considered such (whether unborn children as now, or members of unfavored ethnicities as in the past), then the law should be changed, not the enforcement of laws.
However, this individual who murdered the doctor finds himself in the same place he wished the doctor. The doctor is legally not guilty and the individual guilty. When these persons come before God for judgment, they will both be deemed guilty of the same crime.