Rather than complain about a U.K. publication's possible refusal to play the PC game, or ignorance of how coalface might be stretched to connote blackface (a word that is certainly less freighted over there), why not learn the term as the British use it, e.g.:
"Originally used with reference to miners i.e those who remove coal from the 'face' of the mine, its now more commonly used to mean any work closest to the frontline
"Managers have no idea how hard it is for a sparky these days because they never have to work at the coal face.
"I love pulling apart engines. Its great to get my hands dirty at the coal face."
http://www.urbandictionary.com/define.php?term=coal%20face
"Originally used with reference to miners i.e those who remove coal from the 'face' of the mine, its now more commonly used to mean any work closest to the frontline
"Managers have no idea how hard it is for a sparky these days because they never have to work at the coal face.
"I love pulling apart engines. Its great to get my hands dirty at the coal face."
It's actually complementary to most of us....