I am reading this website and don't understand why this circuit doesn't blow up. If Vin = Vcc then seems to me top opamp A1 would drive low (Vcc > 2/3Vcc and inverting comparator) and the bottom one A2 would drive high (Vcc > 1/3Vcc and non-inverting comparator). So now you have two opamps driving against each other and whichever one overheats first looses.
There is no issue if the output is an open collector type.
I found the text in the article you where referring to:
As a result the output stage of the voltage comparator is generally configured as a single open collector (or Drain) transistor switch with open or closed states rather than actual output voltages as shown: