No real rationale for 'starting' here summaries-wise, more that I have just finished reading this paper in detail and thought that I would share some observations about it and also its relevance to realist synthesis.

The contents of the paper itself:
Friedman uses a case study to illustrate that within a programme theory, there is often also a 'hidden' theory that may thwart a programme. He argues that the concept of a programme theory needs to include BOTH what people think they are doing - espoused theory (in Action Sciences jargon) and what they are actually doing - theories-in-action. Put simply, programmes may fail when the espoused theory and theory-in-action don't correspond to each other. One might think that those involved in the programme might notice, but his point is this is where 'designed blindness' comes into play.

Drawing on the Action Sciences work of Agyris and Schon, designed blindness is a manifestation (within programmes) of what they have called Method I reasoning - when faced with contradictions, they predict that with surprising regularity, particpants become defensive and try to retain control, protect themselves and/or others and maintain rationality. This occurs at a sub-conscious level and allows the particpants to carry on as if there was nothing 'wrong'. The example Friedman gives from his case study is that when the programme fails delivers mixed outcomes, participants blame each other rather than accept that they might have been doing something 'wrong'.

So what has all this to do with realist synthesis?

1) Theories can come from anywhere.
If in a RS we were trying to understand why a programme we were interested in failed, then not purposively looking for transferable theories that explain why programmes fail would be an oversight.
Of course this raises the question, HOW would we know such a theory exists in the first place? Or where would we look and using what process?

2) A realist 'lens' can be helpful in making sense of things
There is no indication in Friedman's paper to indicate what his philosophy of science is. The only hint comes on page 176 ("... we should be able to predict that people using Model I reasoning will always produce strategies that lead to designed blindness."). Is this successionist causation?
However, this does not matter as realist synthesis does not require the primary data to 'share' the same philosophy of science (i.e. be realist in its orientation). Instead it provides a lens that allows use to reconceptualise and use the primary data to explain causation (of a generative nature of course :-)
So in this paper, Desgned Blindness could arguably be conceptualised as a middle-range theory that explains why some programmes fail. The candidate mechanisms in this case would be 'retaining control', 'protecting self and others'and 'maintaining rationality'.
Agyris and Schon's Model I reasoning can be reconceptualised in realist terms to explain why it might act as a transferable middle-range theory (the assumption being that we all 'share' these candidate mechanisms').
In addition, Friedman also sets out the 'Conditions for Design Blindness' (p 170 - multiple stakeholders, ambiugity in intended outcomes and task uncertainty), which may be (in realist terms) conceptualised as contextual influences that are most likely to trigger the designed blindness mechanisms.
Is all the above 'true'? Well the point in any RS is that we might start off with a candidate middle-range theory to explain the 'failure' of a programme, but then we would have to test it :-O

Geoff