Regional Jet 700 ER/LR (CRJ700)
Flight Crew Commercial
Situational Awareness; Human-Machine Interface; Confusion
Aircraft Equipment Problem Critical
Aircraft
On touchdown I noticed the master warning push switch lights flashing; I looked at the display and saw 'R ENG LOW OIL PRESS.' I then looked down and saw the #2 thrust lever in the shut off position. I then said out loud to the captain who was flying; 'number two is shut down.'  He continued the landing roll out without incident. My main concern was why did it shut down; the [loss of required] cooling time for that engine and [the fact that] our left reverser was MELed; so we had no reverse thrust available. We then wrote up the discrepancy at the gate and contract maintenance cleared the write up.Maintenance said it was possibly due to dirt and buildup in the shutdown lever detent allowing the thrust lever to jump past the [flight idle/run position] and [drop into the] shut off detent.We need to be extra careful when going to flight idle; be aware that this could happen again and to check that the shut off levers are [fully seated in the flight idle/run detent].
A CRJ-700 flight crew noted a R ENG LOW OIL PRESS warning during landing roll out and were surprised to discover the right engine fuel shutoff lever had independently moved to the shut off detent.