We all have our pet peeves, and this is one of mine, too. But it's surely orthogonal to issues of code reliability—someone can definitely write flawless English but terrible code, and it's definitely believable that the reverse could happen—so it's not clear what's the relevance here.
Honestly, the biggest thing it tells me is that this is likely a one person project… there was clearly no one proof reading or reviewing this text. I am always a bit suspect of relying on single person projects.
> In case one file is damaged, FSArchiver will restore all the other files from your archive, so you won’t loose all your data.
Loose instead of lose is one my biggest pet peeves, and it appears at least twice on the main page!