Mechanically centered object in Illustrator is not actually centered.

[timmeinhart]

I created a file that is basically a tall box with circles in it meant to indicate drill holes on a post. The drill holes are mechanically aligned to the center of the box in order to have the holes be perfectly centered. When I sent the file to the guy who was going to drill them, he told me the holes were off center. I verified this with a third part as well as printing it myself and checking with a tape measure. 

Why would something that I aligned come out not aligned when printed? 

Below is a screenshot of the file and a close up of one of the holes with a pink line I added and aligned to center. The holes on the far right post (T) are almost 1/8" off center yet when I align them, nothing moves. File is attached. Let me know if you have the solution or if you see the holes as centered or not. 

CC link to the file: https://assets.adobe.com/id/urn:aaid:sc:US:b2aa3827-f402-4fe8-a435-eb1ebf2659b5?view=difile

[didiermazier]

If you try to center the holes with the grey line and it doesn't work it may be caused by some locked object or layer.

I could not check the file because it is just a snapshot online. Please send an AI file.

[Jacob Bugge]

Timm/Tim,

Since no clever suggestions (apart from the one by Didier about your linking to the actual AI document) has arrived yet, here is a maybe silly one:

What happens if you save a copy of the document to PDF and everyone prints from that?

This is based on the assumption that (you have made sure that) the holes are centred in your AI document.