I just got home this evening and it's dark already but I put the RCM back in (took less than 5 minutes) and I decided to try to start it and this time the engine fired up and then immediately back off again. I did this twice (while also trying giving it a little pump of the accelerator) and on the third time I got nothing again.

I'll take the RCM with me to work tomorrow and give it the once over again.