> He just effectively argued that there are no illegitimate targets in war

No, this is not what I've said.

> because soldiers can be anywhere and that hospitals must be targeted or else they are "get out of jail free cards" whatever the fuck that means.

The law is clear in this regard. If you use hospital for military purposes, it is a valid target.

> War is war, but war crimes are still war crimes.

When a hospital is used for military purposes and then attacked, it is not a war crime from the PoV of international law. You may not like it, but it is a fact.

> No point trying to have rational discourse with someone advocating for war crimes.

I think you are irrational here. Your reasoning is based on emotions, and not facts.