I believe (as you said) the accuracy of the last point is gps accuracy.
Which means that the trail that everyone seems to be following could be on the other side of the headland for all we know. Around Clarke's Beach, for example. I don't think we can select certain gps points as accurate and other gps point(s) as inaccurate. Especially as no-one has been able to mimic Theo's apparent gps points other than 'parts' or 'a part' of the points.
That 60 degree angle covers pretty much all of the headland, and does not (it seems) cover Tallow Beach. Not from diagrams we have seen, anyway.
Which is why I have said several times, the gps and ping data does not line up.
The data tracking would be reliable and the tower ping more broadly encompassing an area. Stick with the tracking.