First, my understanding is that only the subjects of a monarch are required to bow. Miss Manners says so in Miss Manners’ Guide for the Turn-of-the-Millennium. Second, I didn’t know bowing was a custom in Saudi Arabia to begin with. I have never been to Japan but I understand they bow there and with a definite protocol to the depth of the bow, but I’ve never heard of it in the Middle East. Thirdly, are you sure he didn’t just trip? 
Fourthly, I think he made a mistake. And I have left-leaning politics and I voted for him.
Not true!
Bush’s hand is on the inside, being held by the Saudi Prince. That makes W. the bottom in this relationship, the bitch of the Saudi Prince.
Thinking about that, ewwwwwwww!
That’s funny; I’m right-leaning and did not vote for him, and I think it was a gracious, symbolic and/or diplomatic gesture. The US could stand to be more polite to other nations, at least superficially. We can always blow them up if they don’t cooperate later. 
Anyway, I think the general rule for all etiquette is the that you should do what puts other people most at ease. All the long lists and specific rules are pretty much subservient to that ideal.
Many years ago I was a banquet waiter for a hotel that was hosting a huge Rose Convention. Rose growers/florists were coming from everywhere to this thing. The guest of honor was a British countess and the banquet manager instructed us in the courtly bow, which frankly I’m not even sure is necessary for a countess (this was before the Internet or I’d have looked it up.)but it didn’t matter to me if the custom was falling on your face, crawling forward on your tummy, and licking her ankles- I wasn’t going to do it and said so- politely but firmly. A lot of the people who’d been practicing their bows and curtseys hadn’t really thought about the “I’m your inferior” notions of it til I pointed it out, whereupon they became indignant as well. The banquet manager (a total prick) tried to make an issue of it and addressed the GM who, surprisingly, was on our side: “This is America, we fought several wars to get away from that kinda stuff”. (Ex military good ol’ boy, which worked in our favor.) So to the indignation of the banquet manager it was resolved: treat her respectively but like any other guest.
When she arrived and took the stand to deliver a speech we all had to go in the back and fall apart laughing. She really was a British countess, but she was from Texas and had one of the thickest drawls you’ve ever heard! She was a countess by virtue of marriage to an Earl (I’m guessing- though I’ve no idea- it was one of those “richer than God American weds penniless guy with title” things). She was also a super nice person who talked to all of the banquet staff exactly the same as she did anybody fawning over the roses named in her honor.
I was also a bellman at a hotel when a member of the Saudi royal family stayed with us- either a younger brother or nephew of the king, but whoever he was---- BLOODY rich. He was buying a huge amount of property in the area (later resold before it was developed) and booked literally dozens of rooms for himself and his entourage who arrived by private jet in Atlanta and then convoyed by limo from there to Montgomery (3 hours). Since the hotel was hard up for cash (has since changed ownership several times) it had to go well and we were all given etiquette lessons before hand. We weren’t instructed to bow or anything like, but we were not to make eye contact, not to any of the “robe wearing guys” in any way unless they addressed us first, and no woman was to enter his rooms to clean when he was present (luckily he was gone several hours each day). The main thing I remember about their stay was that several of them bought very expensive booze while here and left it in the room as a tip to the bellmen when they left since they couldn’t take it back to Arabia; I got a bottle of Courvoisier and some got some very expensive wines and liquors. (They also left a big tip for the hotel staff that to this day we’re pretty sure was a LOT more than the pittance we got [about $20 each and by all accounts it was a stack of hundreds- the GM and others pocketed most of it]).
FWIW, I’m watching the rebroadcast of this week’s Frontline right now and about 5 minutes into Black Money is a shot of Bush the Elder practically hugging a Saudi prince who has come to be known as “Bandar Bush” for his close ties to the family.
I send him Snopes and anything else I can find that wasn’t banged out on a computer in some guy’s mother’s basement, and yet he refuses.
I got a reply from his daughter. She is asking me where exactly the quote I provided says he followed etiquette. So “etiquette” and “courtesy” can’t be used interchangeably? Isn’t that what etiquette is?
Specifically Leonore Annenberg when she greeted Prince Charles on his visit to Washington in 1981. And, significantly, she defended herself on the grounds that she had done so routinely when her husband had been the US ambassador in London.
This is mentioned in the recent Times obituary for her.