I am interested in the time of day of the accident, after a 170 nautical mile transport. I suspect this crew was well into a shift that started that morning, perhaps the pilot was pushing the maximum duty day of 14 hours.
I don't know if this base was NVG equipped. I believe that all Air Methods are and have been for a few years. The company position that NVGs be on your person or locked away discourages 24 hour carriage. Often only the aft baggage compartment is eligible for cargo carriage and lockable. The med crew does not typically have a key and uses that compartment for supplies.
If this crew's duty day started very early, the handover of sensitive equipment may have not been completed and the NVGs would have been locked away at base, not available to the crew.
If this was, as I guess, a hospital to hospital transport, each transfer could have taken hours. An hour at each hospital is an approximation of a quick transfer of care, but it can take four to six hours at the sending to prepare the patient. This flight could easily have started at or before 1400 hours local time, and NVGs might not have been seen as a priority.
The leg from Madison (receiving hosptal) to the base, Woodruff WI roughly follows a highway, US 51. Being low enough for CFIT over a traffic artery more than an hour from the departure and only a few minutes from the destination, late in the shift, implies some pressure to complete that leg and perhaps a willingness to accept an en route altitude that violates company policy. My memory is that that policy was minimum 500' agl daytime, and 1000' at night. The location and nearby METARS do not eliminate the possibility of local fog....
I believe that altitudes are included in automated pos reps to company flight following, and I believe to Ops Control Center. I hated advisories of obvious issues and queries on my plan and position, but they are/were a part of the job with the company, "Yes, I see the thunderstorm ahead. Your graphic depiction is 10 minutes old, it is moving/dissipipating, no issue".