There were some sections of the video where you could hardly see Amy let alone the belt because of people standing in front of the camera but good luck with that.
I suspect just totalling up how many hours she runs/walks will see her fall short of the supposed 20hrs per day. I look forward to seeing what you report from the overnight videos.
I couldn't really figure out what her 'system' for breaking the record was. There were periods where she did 1-min run/1-min walk but generally it just seemed like she got on the treadmill ran until she started to get tired, walked for a minute and then went back to faster. Then went for a 20 minute break. Breaking a record like this is much easier with a system.
I'd say she should have been doing a lot more fast walking with some bursts of actual running. Rather than 3hr30 of slow running with 30mins of walking, she could easily have done 16 miles in 4hrs of just walking without any of the impact/stress of running. Don't believe what I saw in those 5 hours was sustainable for 7 days.