I was initially wondering why there would be a pushback or towbar involved if the aircraft was indeed on taxi out stand 28 as reported.
That 'Power out facing North-West on taxilane K1. Taxi out via taxilane K1.' instruction quoted earlier seems to be removed in the latest Jepp revision.
But, the crossbleed start guidance is still there: 'No cross-bleed start-up by ACFT is permitted till the push-back and/or pull ahead procedure is complete and the ACFT is aligned with the taxilane/taxiway center-line marking.'
So, was the plane towed to K1 after the first engine start to assure clearance to run up the power to start the second engine? And to avoid a higher than usual thrust setting on one engine with a row of aircraft behind on stands 34 through 40?
Whatever the case, APU inop start is an unusual situation, everyone's startup workflows are not normal, there are several options and I always try hard to make sure we all have the same plan. Sometimes you start one engine in the blocks, sometimes two if the huffer hose and connection permit, or do the crossbleed start etc.
And, speaking of single engine taxi, there is some PTU or something that makes the A319 sound like skeletons on a tin roof back in the cabin during single engine taxi as I recall from riding in one a while back.