Well I can tell you infectious development don't do that, it makes the super high contrast that litho film has and also makes point sources get big on film etc. It doesn't make trails. My thought is you shot the scene then picked up the camera and toted it to another spot thinking the shutter was closed. It may have been set for a much longer time than you thought or it stuck open for a while. The original, correct part of the exposure made the seed part then the camera movement made the wild trails.
By any chance was it pretty cold where you shot? That could contribute to creating that problem.