Your proposal is NONSENSE
1) This Neutron star is moving at 3 million mph
2) It has approx one Solar mass (1.9 e30 kg)
Assume a Jupiter-sized body hit it...
Mjup = 1.9 e27 kg = 1/1000 MSun
Therefore, the planet must have been travelling at one THOUSAND million mph This is FASTER than the speed of light.
Either you have discovered a whole new physics that allows planet-sized bodies to accelerate to the speed of light, and beyond
OR
You are talking total nonsense.
I leave it to the educated reader to decide...