I have noticed a peculiar behavior in Trados Studio.
When you double click a word in a segment (source or target), Studio will normally highlight the word + the white space just after the word, if any.
However, if you mark the last word in a line, Studio will never mark the white space just after the word.
I think it would be better if Studio is consistent in order to avoid double white space in translations.
I guess many translators happen to accidentally make double white spaces because of this.