I think "egregiously" is a bit harsh, the basic skeleton of what happened is there, but yes I've been set straight after more study. I was told years ago that it was the US that put them in that area, so it stuck with me. But it was the UK that put them there more than anyone.
This guy does a very good job of breaking down the whole situation:
One thing that I didn't know was that when the UK left the area in 1948, Israel declared itself to be an independent state and displaced even more Palestinians using their military. This of course infuriated the Arabic nations around them, and they had the six day war in 1967 in order to create a unified Arabic state. Israel trounced everyone and took even more land for themselves after that.
In the end, it still comes down to the same issue: They wanted to be put there because of their religion. The people there were pushed around and now have a giant foot on their neck. What we're seeing now is their desperate final struggle before they are wiped out. It's a horribly sad situation.
He kinda glosses over the circumstances in 1948 when Israel was established. He says, "that state was largely recognized by the international community, but not by many Palestinians." Then he jumps to 1967.
He totally overlooks/ignores/avoids that on the day Israel was declared an independent nation, Egypt, Syria, Jordan (then Transjordan), Iraq, Yemen, Morocco, Saudi Arabia, and Sudan ALL declared war on Israel.
Day 1. Their objective - "drive the Jews into the sea." They were unsuccessful in accomplishing this goal, and their war to eliminate Israel ended in stalemate. Once a ceasefire was declared, Jordan laid claim to the West Bank and Egypt grabbed the Gaza Strip. Despite their claims of "Palestinian land," Palestinians did not govern any of the land that is now Israel, ever. It belonged to Ottoman Turks, then Brits, then Jordan and Egypt. It wasn't until 1994 that Palestinians gained any sovereignty, in Gaza, and they elected Hamas as their government.
Of course, Israel was hit with another simultaneous multi-nation war in 1967, this time being attacked by Egypt, Syria, Jordan, Iraq, Saudi Arabia, Kuwait, Lebanon, Pakistan, and of course the Palestinians. And as you probably know, Israel decisively kicked ass. It isn't called the Six Day War for nothing. At the end of hostilities, Israel held the Sinai Peninsula, Gaza, the West Bank, and the Golan Heights. Sinai was returned to Egypt after a few years in a negotiated peace agreement, and Egypt formally recognized Israel. Their enemies still vow the complete elimination of Israel though (see Hamas' founding charter, and Arafat's rejection in 2000 of very favorable conditions negotiated by Clinton, because the entirety of "Palestine" wasn't being "returned" to them). But they also say peace and stability will only return to the region when they are given back the land lost in the 1967 war they started. Sorry, I don't believe that for a second. And it wasn't even theirs then, it was Egypt's and Jordan's.