Yes, yes... that what it was. Darwin said so himself I'm sure...
Well Alfred Russel Wallace certainly never accused Darwin of plagiarizing -- and the two spent decades collaborating after On the Origin of the Species.
Don't you think he just might have said something? The fact of the matter is that Russel stumbled on the outlines of the theory. However, Darwin's Origin of the Species is far more sophisticated and fleshed out than what Wallace had been working with. At least Wallace himself seemed to have thought so... but what did he know!