I've done it for several years and as long as the company SOPs and crew training are adapted to nvg fire fighting, it can be done safely.
The largest detriment of nvg flying is reduced depth perception, reduced sense of rate of closure, and reduced ability to judge height above terrain. So crew training has to address these areas of higher risk. We use additional CRM callouts that include VSI and radalt along with standard cockpit calls to help paint a mental model of surrounding terrain and position of aircraft in relation thereof. At night we increase our standard drop height a bit to allow for a higher margin of safety. We don't do vertical reference on goggles so our procedures in the water source as well as on the drop over the fire had to be adapted to account for not utilizing VR. The drops were easy to adapt to - fly it like an airtanker and keep your speed around 60 KIAS and adjust the start of the drop due to a different sight picture. In the water source it is constant CRM and use of searchlights to help hold position.
The fire puts out a lot of light and helps illuminate the surrounding terrain so that we use unaided sighting techniques as much as reliance on goggles.