There isn't a difference. One memo writer decided to put in in and the other didn't. Again, memo's are not written as perfect answers, they are written as guides for the marker so the marker would read either of these and understand how to mark this question.
I think you might be overthinking all of this because in this very old past paper they didn't include it. So let me be clear: Put in the premium column always. If they give you an allocation, use it. If you are asked to work backwards, include it (like in this case). Just include it and ignore how they did it in this old past paper. In the exam, they will be very explicit in what they want from you and will explicitly tell you if all the premium is allocated to the policyholder's (or unit) fund.
The "insurer's fund" is a very old name for the non-unit fund so please don't taking layout tips from the old syllabus.