"One dude" literally one of the leaders of the PLO. Probably somebody I'll listen to over you, specially when it comes to definitions.
Palestine ever being a nation is ahistorical
But EVEN if it wasn't the case, which is not, that wouldn't even justify colonization since people were still put out of their homes, killed and systematically oppressed.
The origin of the problem is therefore the British, the UN AND Israel who followed up on the colonization, not Palestinian who fought against the oppression.