Injector pump - locking it

I'm busy doing the timing belt on my 200TDi and have found something concerning. The instructions (landrover svc man) say you need to lock the injector pump shaft before you remove the old belt. First something is inserted in the front of the pulley and once that's in then you remove a little plate thingy and then tighten a bolt on the side of the pump. Firstly, why does this bolt need to be tightened? Won't the tool in the front do the job? Secondly, my real concern is that the little plate thingy is missing and the bolt was tight. Which means the last bloke to do the job never loosended the injector pump locking bolt when he finished. Am I correct? If so, what are the consequences?
Before I started this job, the engine was sweet as a nut - this is only a precautionary job.
Any ideas fellas?

Just align up the timing marks on ALL pullys.
Then put a tipex mark on ALL pullys.
i think from memory you can insert a 8mm bolt in to the injector pump pully to hold it still while you remove the belt.

if the pullys move you at least have the tipex makes to go from

Thanks.
I was a bit apprehensive about this, but I just went ahead and stripped it today, locking it as suggested. Now that it's in bits I understand how it works and it makes more sense.
From what I can see, the pin really dictates the timing, the pulley is not really relevant, as long as it's locked to the front of the pump which has the pin in, everything should be ok.
Hopefully LSUK will be able to test the pump and injectors for me next week.

Make sure when you have put it back together you turn the crank 2 full rotations to make sure the belt is on correctley and the valves clear.

hi your correct the pulley on the pump can move around as long as the pin is locked into the pump you should not go wrong as long as crank pulley lined up on marks and camshaft pulley lined up on its mark the pump the movement on the pump pulley helps when fitting a new belt as they are quite tight good luck tiga.