Latins a weird language because its more interpretive. You tell what its saying by the words taking different forms. Iactus isnt the verb, est is which means is. Think of it the way yoda would talk. 'cast, the die is'

the emphasis would be different depending on which words you put first, but it's the same meaning. sentence structure in latin is based on word endings rather than the order of words like in english. you can take the words and scramble them all together randomly but if the endings are correct the meaning won't change.

in this case he just switched two words. it means the same thing.