Ground pin limitations

If I have circuit with arduino that carries a load of say 300mA(a stepper motor). Can a single arduino ground pin sink 300mA?

the second post here seems to say yes

This says no

"In electronic circuit theory, a "ground" is usually idealized as an infinite source or sink for charge, which can absorb an unlimited amount of current without changing its potential." per wikipedia

Assuming the voltage current source is coming from "somewhere else", the ground current is going through the Arduino board, but not the ATmega chip. The board should be able to handle 300mA.