Don't like it, turn it off.

Apparently he does exactly that, when possible. From the Telegraph article:

I am writing this, at home, on a computer on which pretty much every function (apart from the one making the characters appear on the screen) has been disabled. But when I'm at the Top Gear office, the desktop word engine provided for me there constantly attempts to correct my grammar.

Possibly the IT people at Top Gear are to blame for limiting user access to and control of functions like these.