Dear litesong,
It sounds like you had alot of different things going on that day.
It is difficult to be a Mindful Reiki channel under the best of conditions. Perhaps this was a graphic lesson for you that Reiki is a more serious thing than you previously surmised.
So as to theorize for example; not the Reiki's fault necessarily anymore than it would be if one took the cold medicine on an empty stomach and got ill.
Namaste,
Micael