Star Wars Fives moment.

While attempting to take Ringo Vinda from the Separatists, Fives witnessed the death of Tiplar, a Jedi General executed mid-battle by CT-5385 "Tup." A chain of events was set in motion by the preemptive execution of Clone Protocol 66, leading Fives to discover a conspiracy involving inhibitor chips, a plot to destroy the Jedi Order, and—to an extent—Supreme Chancellor Sheev Palpatine's connection to it.

Regarding Tup:

Tup continued his service in the 501st at the Battle of Ringo Vinda. However, during the campaign, his behavioral modification biochip malfunctioned, resulting in him executing Clone Protocol 66 prematurely and killing Jedi General Tiplar.