It seems to me there are two "subjects" here that are getting muddled: 1) the academic question: who is a worker, who is a capitalist and 2) the reality question: in a conflict between the two, who will fight on the worker's side and who will fight for the capitalists?
So far as 1) is concerned, I retain my original position that in order to be a capitalist, you need to have capital -- enough capital that you don't have to work to live and therefore a completely unambiguous relation to capital: should it ever be threatened, your life is threatened. [I leave out the obvious about capitalists controlling the means of production and, in fact, the state, because I don't think either of you would argue that the big capitalists are not capitalists.] But, I think 2) is the more important issue and also the locus of great porousness. When times are good, the working class (including the controllers/intellectuals) are every bit as likely to identify the interests of capitalists as their own...and enjoy the bread and circuses; when times are bad, class divisions become more obvious and even commented on. It then becomes extraordinarily important who one identifies with...and these identifications are by no means automatic. It is in this case that it becomes more important than ever to win over the workers from fascistic demagoguery and the intellectuals/controllers from fear and loathing of the workers.
Joanna