Indeed having just found the footage in a BBC on line archive as part of the 'Task Force South' series made just after the war, The SAM hitting the Dagger footage is mostly likely that taken from the TV tracker of the Sea Wolf system which did the engagement. Sea Harrier engagement is also on the footage (I remember it being described as a SHAR shooting down a Skyhawk on the news reports at the time, but you're right in saying that the aircraft are dots in sky), as well as the 'Skyhawks' dropping bombs, that at second glance look like they are actually Daggers.
Link to BBC ‘Task Force South’ series is
Here. Tracker footage is in ’Beach Head’ link from approximately 08:30 to 10:00 into the programme.