Posting those graphs really was goiong to bring out 1000s of Amateur accident investigators (of which I would be one if I decided to read too much into them... )
Seems that just as ENG1 idle rev was selected, ENG2 accelerated from approach ~1.09 EPR to ~1.28 EPR and then stabilized to around ~1.19 EPR.
Eng 2 appears to increase power as Eng 1 reduces power from the TL movement... which is entirely logical while ATHR is engaged to maintain an IAS etc. It is clear from the Graphs when ATHR was active etc.
Why would ENG2 accelerate, even though it was left to CLB. Shouldn't the Thrust Lock have just locked it to ~1.09EPR.
Why should it maintain 1.09 when ATHR was engaged and Eng1 EPR reducing and IAS reducing (slightly)... seems to be to be working as advertised
NB the ATHR system sees one engine as essentially "failing" so applying power to the other one to maintain speed is surely what you would hope for?
NoD