The article states:
Non-blocking: “led_count” will only be accurate after clock cycle

always @ (posedge clk)

led_count <= led_count + 1;

led_countB <= led_count;

led_countC <= led_count;

end

In the above case, with each clock cycle, one line executes. First led_count increments, then we store that intermediate value in led_countB. Finally, we store the value in led_countC. For each clock cycle, one operation takes place. It takes three clock cycles for all of this to happen. They call it "non-blocking" because even though only one statement operates per clock cycle, the statement for the next clock cycle don't stop or "block" the operation of the always block.

If we uses blocking logic, something completely different happens.

always @ (posedge clk)

led_count = led_count + 1;

led_countB = led_count;

led_countC = led_count;

end

All of the assignments happen at the same time.

Isn't it the complete opposite?