Flight Crew Air Transport Pilot (ATP)
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem; Flight Crew Became Reoriented
Aircraft; Human Factors
APU was deferred; so commenced with a bottle start of the right engine. Noticed the pressure seemed low (18-25psi?); engaged starter and introduced fuel at N1 indication.  I was anticipating a failed starter cutout and put my finger on the Starter Cutout switchlight. Spool up was gradual; then IIT quickly went above 900deg. Captain called for engine shutdown and I inadvertently pressed the starter cutout instead of moving the thrust lever to Fuel Shut Off position. By the time I realized what I did and before I could shut down the engine; ITT was below 900deg and the engine indication were moving toward normal indication so we elected to not shutdown. Since the HOT icon didn't appear and we knew the reason for the high ITT (low bottle pressure) we decided it was safe to continue. At [destination] we discussed the situation with Maintenance and told us we need to write it up.I was anticipating a failed starter cutout (almost every bottle start requires the manual selection of starter cutout) and improperly responded to the Captain's call for an engine shut down. There was potential engine damage if the engine didn't return to normal parameters with the delay of the engine shutdown.I need to slow down and not presume what is going to happen. Review engine shut down parameters before a bottle start. A question I have is why there are no guidelines for minimum psi for a bottle start like there is for the Cross Bleed start?  At what psi should you not attempt a start?  I am not sure but at one time didn't we have guidelines for the minimum pressure of a bottle/huffer start?
CRJ-200 First Officer reported responding inappropriately to a hot start and then failing to write up the anomaly.