CDL 04-05 & CDL 05-06 Question

[mellody]

Some question of this CDL after a watch it a bunch of times

1. I'm pretty sure that Ayu sings wrong part of the lyrics in evolution here~
When entering the second chorus, why she sang the lyrics of the first chorus?
Yea, i mean like this, Ayu sing :

Spoiler:

kono hoshi ni umaretsuita hi
kitto nan da ka ureshikute
kitto nan da ka setsunakute
bokura wa naite ita n da
wow yeah wow yeah wow wow yeah

that part in the first chorus and second chorus, and then followed by :

Spoiler:

konna toki ni umaretsuita yo
da kedo nan to ka susundet'te
da kara nan to ka koko ni tatte
bokura wa kyou o okutte'ru
wow yeah wow yeah wow yeah

Where is this part?

Spoiler:

konna hoshi ni umaretsuita yo
nan da ka totemo ureshikute
nan da ka totemo setsunakute
ookina koe de nakinagara
wow yeah wow yeah wow wow yeah

If she's wrong usually she have a smile or expression saying gomen, or something like that, isn't it?? or maybe i was wrong??

2. They also shout some words that sounds like "Soya" or something sound like that (I thought it was Shu-ya at first~)
What is that means? and why??

Please explain it to me~
Thanks~