Just to speculate further - Maybe everyone tends to read an unfamiliar language hyperlexically.  I can understand a lot of Chinese characters without knowing how they are pronounced in any of the various Chinese languages.  Of course, Chinese writing is an extreme example here because it wasn't originally an alphabet to represent the sounds of spoken words, but a big set of pictorial symbols for things and concepts.  My wife's first language is Cantonese-Chinese, and she says that she reads English as I do, by recognising whole words instead of subvocalising (BTW, she's not on the spectrum).  And we both like to watch DVDs in English with the English subtitles switched on - it's easier to read than to decipher actors speaking in unfamiliar accents.