As far as I can see, Niven dealt with two of the three ways that Beowulf Schaffer would have died in "Neutron Star" but not the other. The ways were:
Tidal forces spaghettifying him. The extreme tidal forces near a neutron star are powerful enough that no known material -- and certainly not human bodies -- could remain intact, but instead would have been stretched along the axis pointing towards the neutron star until it was a very long, very thin line of specks of human body.
Radiation from the pulsar. A pulsar's radiation is so strong that even if you accept that the super-high-tech, unobtanium-fueled, never-needs-washing, radiation shield of the GP hull would stop everything it is supposed to stop (very dubious unless it's actually using magic) the gaps in the shield for the visual ranges of client species would let in enough energy to fricassee the contents. (So Beowulf would have been a very, very long, very, very thin line of vaporized human body.)
The pulsar's accretion disk: The equatorial plane of most dense, massive object contains a disk of very, very, very, hot gas produced by infalling debris that has too much angular momentum to fall straight in -- a vast majority of infall. The process releases a lot of energy which creates the accretion disk from the vaporized debris. Hitting it a a thousand or ten thousand kps would be like hitting a mountain side: Even if the GP hull survived, the contents would be toast. (Making Beowulf into a very, very long, very, very thin, very, very squashed line of vaporized human body.)
In "Ghost: 2", one of a number of bits Niven added between the original Beowulf Schaffer stories, Schaffer takes pains to point out that this was not the first neutron star discovered, but the first old, cold one:
First old, cold neutron star...."You couldn't dive that close to a pulsar. Even a GP hull couldn't bash through the accretion disk."
So, there's a plausible solution to everything but the tides.
