The 2MASS color-color diagram is here . All sources are within 17 degrees of the ecliptic plane. The 3-band sources tend to be somewhat closer to the ecliptic plane than the overall distribution . The two low SNR JK sources are faint persistence. Both high SNR and the single low SNR HK sources are flagged as unreliable.
Visual inspection shows they are meteors.
One is flagged as persistence, which it clearly is. It is brighter than expected on the images compared to the other persistence artifacts, which is why the persistence probability was not high enough to exclude it from the PSC altogether. They may be asteroids or other real sources. Thus, the fraction of these sources which are spurious is unknown. Two others are faint persistence artifacts.