L-20 Improved Push Pull Amplifier

This video explains the reduction of dead zone or cross over distortions in push pull amplifier

[@datdoesthings]

Hi,
I don't understand from 5:03 why the output due to Q2 is V_out = V_in + V_be2, whereas for when it is connected to Q1, we see it as V_out = V_in - V_be2. Could you kindly explain?
Thank you, best
Matthew