Also, as you read the script you see that Cloud was a complete loner. He got into fights, was antisocial, and had no friends. It is extremely likely "We" is wrong. He is also talking about himself in that passage, so "we" wouldn't make much sense anyway. And of course, Luksy used "I". Placing any faith into the original translation is fairly foolish because it is awash with mistakes.
Also note that Covarr is going to go through all the text and point out any errors he sees. Grammar issues such as numbers are small fry, and not even writers all agree on what is what. "It was five years ago, I was 16" would look silly to me. I tried to add in consistency when talking about dates and times. "There are four balls" "It was 5 years ago, I was 16". I may change that if Covarr thinks it needs doing on his run through.
I am not plucking things from thin air, basically. I do think about all this.
Consistency is most important with numbers. I am looking at those links, and others, and there is disagreement even there as to what is accepted. It's basically up to the writer. I don't see anything wrong with "It was 5 years ago". Not to mention a lot of the time, the dialogue boxes look much better for using numbers rather than spelling it out.
We'll see what transpires in the proof check!