HK Employment Visa validity

[Hmm. Hope this is the best forum rahter than Asia / Living abroad]

Any expats out there? We need some explanation of HK work visas please.

One of my workmates is in the process of transferring out to Hong Kong, where he'll still be with our company but employed by the Asian business unit instead of the European one.
He's been issued an employment visa but we’re just a bit confused about the expiration dates

Now, it is an (E) class visa and it has an issue date of 15-07-11.
It says:
Good for a single journey to Hong Kong.
Valid for presentation on or before 15-10-11.
Employment 3 months.

And the rest is in Chinese.

Does this mean that so long as he enters HK before Oct 15th, he has 3 months from entry or does it start from the issue date and he would have to leave by 15th Oct regardless of when he entered ie; his time is already ticking away?

I've had a pretty good look around the HK Govt website and searched GeoExpat too but can only find references to 1 or 2 year employment visas... nothing about 3 month, single entry visas.

Does anyone have any experience with this sort of visa?

Thanks.