"Saudi foreign minister, national security chief both met with Obama in the Oval Office in early 2013."
Ouch.
That doesn't necessarily mean anything without knowing if this subject was brought up at the meeting. But yeah, somewhere a screw-up clearly occurred.
Not suggesting that the bomber was the subject of the meeting but in a wide range discussion, something like this could very well have been discussed.
What raises more flags in my opinion is the fact that the White House and Homeland Security are saying they never received such a letter. So is this just a total fabrication by the Saudis? If not, who did the letter go to?