I pulled up my run on that path from two years ago and saw that I did 6.38 mi for TWO laps with a slight path difference between the laps:
Start in front of BW
Head toward EPCOT IG
Turn RIGHT over bridge.
Gate closed / bollards still up. Touch gate, turn around.
Run in front of BC, then YC, then to DHS path.
Run around the DHS entrance area (including Ferry).
Touch DHS entrance.
Back along path toward EP.
Turn RIGHT at BW.
Run along BW.
Head to EPCOT IG.
Turn RIGHT over bridge.
Touch IG.
Run in front of BC, then YC, then to DHS path.
Run around the DHS entrance area (including Ferry).
Touch DHS entrance.
Back along path toward EP.
Instead of turning RIGHT into BW, stay straight straight toward YC, BC.
Touch IG.
Turn LEFT at BW bridge.
Finish at starting point.
It was the fact that I did the "long" side of the lake 3 times (instead of 2 on each side) and that I went around the whole DHS entrance instead of directly to bag-check that made it longer than 3 miles each lap.