My guess is that such a person may fail the attitude test.
Indeed, and I'm guessing they'd be looking at something mentioned by the laws referenced in HWC rules 68 to 71 in the "Rules for Cyclists" section.
I don't have time to sift through them all to check.
The two ones that jump out at me are:-
"
71
You MUST NOT cross the stop line when the traffic lights are red. Some junctions have an advanced stop line to enable you to wait and position yourself ahead of other traffic (see Rule 178).
[Laws RTA 1988 sect 36 & TSRGD regs 10 & 36(1)]
"
There may be something in either of these laws/regs that may even prevent dismounting and remounting the other side of the line.
Then there's the catch-all of:-
"
68
You MUST NOT
* carry a passenger unless your cycle has been built or adapted to carry one
* hold onto a moving vehicle or trailer
* ride in a dangerous, careless or inconsiderate manner
* ride when under the influence of drink or drugs, including medicine
[Law RTA 1988 sects 24, 26, 28, 29 & 30 as amended by RTA 1991]
"
It could be argued that such behaviour is inconsiderate to the other vehicles/pedestrians at that junction although, again, it depends on the wording of the relevant law.