Good point DG. I wondered at the adjacent switches potential for incorrect selection. A VERY long time ago, in 1979 at UK (CAA) certification of the Agusta A109, I was involved as co-ordinator and I remember only too clearly that, on the fuel management panel (between P1 & P2 seats), CAA required that the fuel valve shut-off switches were to be made "tactilely discernible" from the adjacent ones. This comprised 1, 3 & 2, 4 fuel boost pumps and, centrally, a latched fuel-cross-feed switch. The rationale was based on UK certification requirements for IFR operation and at night; it was to be another, physical, cue of what service you had just selected even if you couldn't see it.
I have had the locations in the EC135 demonstrated to me; seems it would not be difficult to select the wrong switches, and, convinced you had selected the correct ones, just fail to believe all the warnings subsequently presented.
I should add, clearly, this viewpoint comes from an engineer, NOT a pilot. Ready to accept any criticism that may abound _ VFR