Aside from the fact this is being discussed at length in the "Tisdale to Bristol City" thread, people will often go to interviews not necessarily "wanting" the job although they could be swayed if they liked what they saw at interview.
Maybe his 'ironic' wave to the BB on Saturday was in fact his big emotional farewell?
Would make sense, as I understand it they are just setting out as a Trust-owned club and he has experience of managing a Trust-owned club. And of getting promotion out of this division. Plus it would be a new and bigger challenge for Tisdale, who may well be fed up by now of all the negativity permeating the club. And Pompey could probably afford to pay the £300k compensation from that 'idiotic' rolling contract.