why point fingers at only Umar (ra).... was Umar (ra)'s argument enough for other people present at that time (some of whom you even take to divinity) that they all disobeyed the Prophet (saw)????
Umar lead the pack that refused the pen and paper. Prophet (saww), as stated in the traditions, became annoyed and told everybody to leave. How did you draw out the idea that all of them there disobeyed the Prophet?