Often you will hear people say something like 'He turned round and called me a liar', or 'what if she turns round and refuses to pay'.
This 'turn round' (I am informed it is much less used in America) is only apposite to certain contexts. And what exactly does it mean?
Edit after reading some of the responses
Clearly abruptness and/or suddenness are strongly implied by the expression. But I cannot agree, as some have suggested, that it necessarily involves a reversal of a previous expression. That is not the way it is always used in Britain. For example one colleague to another might say 'If we give Charles added responsibility, he may well turn round and use it as an argument for a pay rise'. That sort of use is quite common.
I think the turning around is not about a reversal of a previous position, but is used to indicate that the remark came suddenly and out of nowhere. In other words the fact of turning around indicates that it is not part of an existing dialogue which had been going on.