AP4306 has paralleled two op amps in it's block diagram, is that possible?
The data sheet states that the outputs that can only sink current. This is very common for comparators to have open-drain(or collector) outputs.

Since they only sink current they do not have normal opamp push-pull outputs and it is acceptable to tie them together.

It also means that there must be an external current source feeding the output - normally this would be a resistor pull-up to the positive rail of the power supply.