The Plan

"The Troublemakers." 

That "plan" must be flexible and adaptable with a lot of safeguards and feedback mechanisms. The psychologists think that Evan Friday has the potential to be a good end-of-voyage Captain so they get him framed and busted down from the officer caste to the labouring class where he might learn some practical politics. If he had not measured up to expectations, then they would have had him exonerated and sinecured but would then have had to find another Captain. Instead, Friday exceeds expectations, organizing the merchant class and leading his "watch" around the outside of the ship to outflank the mutineers - thus saving the ship from an unproductive tyranny and maybe even from extinction? Well, no. The psychologists, having socially engineered the mutiny, must surely have had some other strings to their bow in terms of defeating it? Individuals like Friday can make a very big difference but the plan has to override individualities.

Seldon's Plan is thrown off-course by an unpredictable individual mutant but is flexible enough to get back on course, especially since psychohistorians are still working on it.