More likely the drone calculated it was greater than 65' from the homepoint when it was actually not. There is a lot of assumption that GPS accuracy is always great, especially if tracking a lot of satellites, but this is not always the case. GPS is notoriously inaccurate under trees and +/- 65 feet for absolute position accuracy is not unreasonable assumption. I work with survey grade GPS and I can tell you it is common for a GPS receiver to calculate a position that is 65' off from the actual position when the GPS reception is poor, especially under trees.
And its not so much the quantity of satellites being tracked as it is poor satellite geometry. The more spread out they are the longer the baselines for the math to figure out the position of the GPS receiver. Tracking 8 satellites spread out evenly over the sky will give better positioning accuracy than 16 satellites all in one portion of the sky, like you might encounter standing along the edge of a forest. If you google dilution of precision for GPS you'll find more information, but here are a couple with decent explanations:
Basic GPS and
Dilution of precision (GPS) - Wikipedia, the free encyclopedia
So in a nutshell its entirely possible to be landing within 65' of the home point but have the drone think its not that close and go into RTH mode instead of auto-land.
