No, thats not the case.
Util.checkGLError(); checks the drivers for any error that might have croped up anywhere in the last frame, Util.checkGLError(); releases those errors to be printed or whatever. You could be doing GL11.glLightf(GL11.glTrue); which is an invalid enum for that method call. Check the rest of your program carefully with a very fine toothcomb, if in doubt, put other Util.checkGLError(); calls in your code to see if the error has cropped up anywhere else...
Util.checkGLError() checks the gl error state and finds it clean (otherwise it would throw an exception), after Display.update() completes, I check the gl error state and it is not clean (Invalid Value), so something that occured as a result of Context.swapBuffers() set the gl error state. My code is full of gl error checking already. The gl error state is clean when I call Display.update() and dirty when it completes.