While I don't doubt the induction water heater idea has merit in some circumstances, I don't see it as being consistent with the 'efficiency' objective mentioned in Nilu's opening remarks.
Inductive heating, just like resistive heating, can only have a maximum of 100% heating. I thought the direction for modern domestic water heaters was of the 'heat pump' design and unless you're in a rather cold climate, you can get up to something like 2 to 3 times the heating for the same amount of input power. Also, if operated as an 'instantaneous' hot water supply, you will be subject to full tariff on all electricity used - or if you use storage tanks, then you have the very same issues with those shown during the intro.
I also agree that it would seem the main need for Nilu's project would be differential probes.
I don't wish Nilu J. or her team any ill and I do hope they get a scope to help them out - but the 6000X is overkill for them, IMHO.