I have often heard Michael talk about a painter who copied other artist's styles. He wasn't quite sure who it was.
I noticed that the Tate has an exhibition on a similar theme at the moment. Not sure if this is the person he was thinking of but it looks like an interesting exhibition so I expect I'll go.http://www.guardian.co.uk/artanddesign/2009/may/06/jmw-turner-tate-exhibition
Turner's motivation seems slightly different from the painter Michael mentioned but stories do change.