我觉得在这个事情上他们双方也有错。

Wǒ juéde zài zhè gè shìqing shàng tāmen shuāngfāng yě yǒu cuò.

I think both sides are at fault in this matter.

他们双方始终无法达成协议。

Tāmen shuāngfāng shǐzhōng wúfǎ dáchéng xiéyì.

The two sides still couldn't reach an agreement.

双方达成了互利共赢的合作关系。

shuāngfāng dáchéng le hùlì gòngyíng de hézuò guānxi.

Both sides have achieved a mutually beneficial cooperative relationship.