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Don't have an idea why you would see a spike on the test point.
The pulling could be because the sync separator or AGC is slightly out of spec, or because it's designed that way. The equalizer pulses in NTSC were designed under the bad assumption that the horizontal timing would be derived precisely from the leading edge of H sync, equalizing pulses, and vertical serrations. This was a dumb idea, because an analog H sync circuit with enough bandwidth to get those edges precisely right would be terribly susceptible to noise. Therefore, the input to the sync separator is filtered, which causes the H sweep to sync more towards the center of the sync pulses. This means that it normally pulls somewhat one way or the other during the three types of pulses. That is probably part of what you see - but I also see the video level change, which seems to say that the AGC voltage is changing some. You might try poking around in the sync and AGC sections, and see what happens when you adjust the AGC.
Any problems with streaking in the picture? If not, I would probably ignore this.
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