ESA linking rules and transitional addition

My client was entitled to IB of £104 plus the pence for some years (long term rate plus the age-related addition), but then failed the WCA on being assessed for conversion to ESA in October 2012.

Rather than appealing the refusal he then claimed JSA, but after a month got worse and reclaimed ESA on 14/11/12.  They didn’t initially pay him as it was within 6 months of his previous decision and they presumably didn’t accept the worsening was significant enough (I wasn’t involved at that stage or I would have considered disputing this, I hasten to add) but in any case following another medical he has now been placed in the WRAG, and has finally had his back pay from 14/11/12, but only at normal ESA rates.  This included the first 13 weeks of the claim paid at assessment rate.

Having read ESA regs 5, 7 and 145, I am thinking that because he did not have a previous period of limited capability for work and entitlement to ESA that could be linked to the current claim (as opposed to incapacity for work and entitlement to IB) he won’t be protected by the linking rules, and won’t be entitled to the transitional addition, and can’t avoid the assessment period on his new claim either, and his only way of getting round this would be to successfully appeal the original conversion decision that he did not have limited capability.  Am I reading it right or does anyone have any other ideas?