That he's not president. Or he is, but they have determined him to be something else. Normally they will have 4 cannons with 3 firing and 1 as a backup. Biden had 3 cannons, with 2 firing at the really long intervals. Even if they couldn't fit one or there was another issue, they could have used all 3 to fire at 3s intervals, or even just 2.
Ceremonial military protocol is usually very set in stone
That he's not president. Or he is, but they have determined him to be something else. Normally they will have 4 cannons with 3 firing and 1 as a backup. Biden had 3 cannons, with 2 firing at the really long intervals. Even if they couldn't fit one or there was another issue, they could have used all 3 to fire at 3s intervals, or even just 2.
Ceremonial military protocol is usually very set in stone