""Many people in a position to know were linking the behaviour to aspects of culture.
They were mostly people from that culture.
No other explanation was forthcoming.
Why would anyone not believe them all, and how can it be construed as racist.""

Just one small point Keith, then this particular story is done and dusted as far as I'm concerned.

You say that ""They were mostly people from that culture. No other explanation was forthcoming."", and for that reason you believed them. You were convinced of their veracity, yet when they said that no generalised conclusions about that culture should be drawn from their comments, you chose not to believe them.

What happened to change your mind about their veracity?

Was it perchance that the latter comment didn't fit in with what you wanted to believe?

Don T.