The unexpected happened when a horse threw its rider ahead of the newlyweds' carriage

Sometimes, despite all the planning and the rehearsals, things don't quite go according to plan during a royal wedding procession.

One such moment, etched in video viral history 10 years ago, occurred when a member of the Household Cavalry was thrown from his horse just ahead of the carriage carrying newlyweds Prince William Kate Middleton from Westminster Abbey to the palace.  

But the trooper remained cool and calm and won praise from the man who meticulously planned the layout of the procession, Garrison Sergeant Major Bill Mott.

"To be thrown from a  horse on tarmac is not a nice experience, and he was in his regalia as well," Mott tells PEOPLE.

Prince William Kate Middleton Royal Wedding
Kate Middleton and Prince William
| Credit: Max Mumby/Getty

The trooper collected himself, standing at attention as the couple passed just seconds later. He stood in Parliament Square "as if he is a street liner. He had just been thrown off and here he was standing. I got a message to him a few days later to say how proud I was of him," Mott says.

Mott — a veteran of organizing parades for Queen Elizabeth and her family — was in charge of laying out the exact details of where each member of the armed services was meant to be, measuring their location and timing the movement of the hundreds of troops on duty that day.

Garrison Sergeant Major William Mott of the Welsh Guards
GSM Bill Mott
| Credit: John Stillwell/PA Images via Getty Images

Mott, 60, who is now GSM at the Valley Military Academy and College in Pennsylvania, recalls his work at the royal wedding in this week's issue of PEOPLE.

"I was up at "dark o'clock." [Before the wedding] I had to mark the ground for the guard of honor and the street liners. We did a rehearsal one early morning a couple of days before," he says.

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"Because it was such a splendid affair, everyone was pumped up. Even at 4 a.m. there were people already waving their flags," he adds.

Prince William Kate Middleton Royal Wedding
Credit: Mark Cuthbert/Getty

Once his work was done, he was able to watch from the palace gates as the couple appeared at the balcony.

Listen below to the episode of our daily podcast PEOPLE Every Day as we look back at Prince William and Kate Middleton's wedding 10 years later.

"The crowd was falling over themselves with excitement with 'aahs and oohs.' he recalls. "They were very happy people. It's amazing how close it is when you are there on the ground. It is only 34 paces from the railings to the wall and they are only 15-20ft above you. I'm a soldier, a man's man, but even for me it was lovely to see that."

Tune into The CW on Thursday at 8/7c for a tenth wedding anniversary special, People Presents: William & Kate's Royal Anniversary

And the horse? "He knew how to get to the stables. That's where he gets fed and was bee-lining down Whitehall to get to Horse Guards guardroom," Mott adds of the immediate aftermath of the mishap.