I found that if connect listener to rtsp_server event 'client-connected'(even empty method) descriptors are leak for each client connect-disconnet.
After client disconnet, it left one CLOSE_WAIT connection.
If I remove listener, then no leak, and method gst_rtsp_client_finalize calls on every client disconnet. But with listener it never called.

I found that there are no such problem in C.

My simple test:
 
from gi.repository import Gst, GObject, GstRtspServer
Gst.init(None)
rtsp_server = GstRtspServer.RTSPServer()
rtsp_server.attach(None)
def client_connected(client, context):
    print "Client connected"
rtsp_server.connect('client-connected', client_connected)
factory = GstRtspServer.RTSPMediaFactoryURI()
factory.set_uri('rtsp://rtsp.algont:4000/62wKYOvnazxrv3s8cLIfmr')
factory.set_shared(True)
rtsp_server.get_mount_points().add_factory('/good', factory)
GObject.MainLoop().run()