OP, the law as regards the definition of the restriction imposed by a YBJ:
Box junctions
11.—(1) Subject to sub-paragraphs (2), (3) and (4), the yellow criss-cross marking provided for at item 25 of the sign table in Part 6 conveys the prohibition that a person must not cause a vehicle to enter the box junction so that the vehicle has to stop within the box junction due to the presence of stationary vehicles.Para. 11 Part 7 of Schedule 9 to the Traffic Signs etc. Regs refers:
https://www.legislation.gov.uk/uksi/2016/362/schedule/9We don't need to worry about the exceptions, as far as this case is concerned the following apply:
Did the driver CAUSE their car to enter the YBJ? Of course, they deliberately drove into it;
Did the vehicle HAVE TO STOP due to the presence of stationary traffic? Of course not. Although the artic was stationary, the driver in this case did not HAVE to stop, they CHOSE to stop. Frankly they could choose to stop for any number of reasons, including bloody mindedness, but this would not be a contravention as regards the YBJ.
The definition is clear, there are no judgments or body of adjudication decisions to the contrary so take the stupid b******s to adjudication and ask for costs.
Step 1 - register the appeal.