Emitter follower with sine wave

[the_eagle]

I am reading the famous book Student Manual for the Art of Electronics 2nd ed. and I find problematic to understand one sentence:

If you turn up the waveform amplitude you will begin to see bumps below the ground

When V_EE is connected to GND (0V), even though I amplify the amplitude of the input, the output I should see is a sine wave only on the positive side (i.e. voltage greater than around 0.75V) and the minimum voltage is 0V, not less. I simulated it on LTSpice, too. 

The whole paragraph is attached to this post and it has been taken from https://canvas.harvard.edu/files/1835978/download?download_frd=1&verifier=3PapuqWrt3ZzxRDwEfbtm69fz4T2Qujc6ZP8ALWB.

[the_eagle]

Thank you very much. Yes, obviously it's a sine wave across a diode so when you exceed a reverse voltage, there is a breakdown of the diode.