If your bender is in good shape, set up properly and lubricated, you should be able to bend way past 90 degrees without kinking (in fact, as the portly fellow mentioned in the video, you have to bend past 90 to account for springback). The only time I've kinked tubing with a hydraulic bender is when bending rusty pipe that had been salvaged from an old natural gas system. You won't have that problem with new pipe.
Make sure you grease or oil the shoe of the bender, and make sure the rollers are in the correct holes. Get yourself a set of 2 angle finders or 2 magnetic torpedo levels and a protractor. Alternately, I use mine flat on the floor with an adjustable T square, like this one: