no, this is based on my understanding from the refusal letter and R.80(3)
This is R.80(3)
(3) For the purposes of subsection (1), a skilled worker is considered to have experience in an occupation, regardless of whether they meet the employment requirements of the occupation as set out in the occupational descriptions of the National Occupational Classification, if they performed
(a) the actions described in the lead statement for the occupation as set out in the occupational descriptions of the National Occupational Classification; and
(b) at least a substantial number of the main duties of the occupation as set out in the occupational descriptions of the National Occupational Classification, including all the essential duties.
so you must include those duties in your letter that shows the actions described in the lead statement of the corresponding NOC code , here the lead statement for RA is assisting a faculty member in research activities, so if you exclude those duties which have the term "assisting", the officer would say list of duties in your letter do not match the actions described in the lead statement!!
but this is just a guess! I have to wait for their reply to MP's assistant