Med Error?

I wrote myself up for a med error last night, but now that I have had the time to think about it, I may not have been the one who made the error.

A new admission (I work for a sub-acute rehab) was to receive MS Contin, 15 mg. 1 tab PO q 12 hrs. It was written correctly in the MAR, however only plotted for 10PM (should have been 10 AM and 10 PM) I work the 3-11 shift, so, the patient did receive the dose on my shift. This went on for about 3 days. During report the day nurse pointed it out to me as though it was my fault because it was my admission, however I did not fill in the MAR, someone else did who was helping me that night (we had 5 admissions, crazy night) so I wrote the med error. As I thought about it, did I make the error? Technically no, I gave my dose, it was the morning nurse that missed the AM dose and should have notified the ADON on the error.

I am not looking to escape responsibility here, I should have read the whole order just as much as anyone, but in actuality I gave the PM dose.

A domino affects here, the one that plotted the med, to the morning nurse not reading it, to me. I feel as though the morning nurse was trying to pass the buck to me by pointing out the mistake instead of writing herself up for the error. Oh well, I did the right thing, notified the Doc, wrote the med error report, did my job.

Thanks for any feedback on this!