actually answering my own question in part, it's explained at https://www.hq.nasa.gov/alsj/nasa58040.pdf https://www.hq.nasa.gov/alsj/nasa58040.pdf pp. 21 ff.

actually answering my own question in part, it's explained at https://www.hq.nasa.gov/alsj/nasa58040.pdf https://www.hq.nasa.gov/alsj/nasa58040.pdf pp. 21 ff. : P65 was apparently planned and there was a velocity error amongst others leading to a navigation error. What remains open is what material impact the interupt overload on the command queue had.