It looks they painted the earth connection together with the external wall. Looks neat, but I'm concerned about the continuity. Or should I be?

Just did a test, the resistance from earth socket in one of the room to the earth stick is about 1.2 ohm. (including a HPM extension cable and I sanded the top of the paint on earth stick a bit to get a nice contact, measured by a cheap general purpose multi meter)

Is there any codes saying that you can/cannot paint the earth connection?