[BTW, checked back re' lessons from the fatal AdamAir event of 1Jan2007
EFIS Gyro Stability
but in that case the FO had moved the IRU switch from NAV directly to ATT:
Which is much easier on the 737 as ATT is next to NAV, just pull out and one step clockwise, if the switches are a bit worn it can happen without pulling the switch out and is an easy enough mistake to do on the ground when switching from ALIGN to NAV. Inflight one shouldnt touch those things, except after thorough troubleshooting and when advised by a non-normal procedure.