Pfizer 'got to' O'Keefe's people. Simple as that.
Like 'external entities' got to Glen Greenwald's people at The Intercept, forcing Greenwald out.
The MORAL is: Don't organize your operation by putting specific people in-charge of specific segments of it, governed by a board. -Even vetted, hand-selected people. They can turn.
The same thing was threatening to occur with the TEA Party, but the gambits flopped because Taxed Enough Already had the sense not to organize. They remained a philosophy.