Although to kick back has come to mean "relaxing," it actually means to fight for your right to be idle; to kick against the pricks who'd hold you back; to kick over the traces and kick out the jams. See: BALK, LIBERTINE.
spring back, as from a forceful thrust; "The gun kicked back into my shoulder"
This is when a workpiece is thrown back by a cutter, prevented using anti-kick back devices on power tools such as table saws.
As the machine accelerates out of a corner that it has just cut, the jet will "kick back".