from Igel
".... it was a legal necessity. Finally there is at least some legal certainty."
Hat tip to Igel for this update.

Every difference of opinion on how to conduct warfare should NOT result in a "war crimes" invesigation.

The German statute (Völkerstrafgesetzbuch) looks to the actual perception of the soldier at the time:

3. carries out an attack by military means and definitely anticipates that the attack will cause death or injury to civilians or damage to civilian objects on a scale out of proportion to the concrete and direct overall military advantage anticipated,
Thus, the legal question becomes one of whether the soldier believed at the time that he (or she) was attacking combatants (even though some civilians might also be believed to be there - when "proportionality" has to be considered).

Regards
Mike