With a 10C IMR battery, he can. Even with an AW IMR
18350, 3.7V, 700mAh, rated at 10C, it can provide
7A in 6 minutes; provided that the battery is in good condition. Of coures, if one uses a normal Li-ion battery, even with an
18650, 3.7V, 2600mAh, rated at 1C, it can only provide
2.6A in one hour; mAh: milli-Amp-hour.
In his case, he needs
4.4A with his 0.8ohm coil on his 3.7V battery holder.
P = V * I
16.1 = 3.7 * 4.4
V = I * R
3.7 = 4.4 * 0.8
He is using a Precise+, hopefully an 18xxx, a non-regulated 3.7V device, but if he is using a Provari, he will have a problem, because the 3.5A output current limit of the Provari. You are right, if he is not using an IMR battery, "with god on your side, on the perfect sunny day while the battery was being hit by lightning?"
If you are interested in how the C rating is defined:
Click here
Here is some write up regarding Watt, Volt, Amp for the DID.
Click here