^ I think it only shows date modified and it will be more appropriate to click on the Digital Signature tab and read the date. That is what I do. Correct me if I am wrong .
View attachment 157060
Happens to be the same on mine but. the digital signature date is the date the certificate was signed and could be weeks after the date the file was created. either one gives you good info.
The Raxco Perfect Disk file shows the digital signature date 16 March 2011 in the screenshot I had put.
The date created, modified and accessed as shown in the General tab is 22 May 2011, which is the date on which I downloaded the file and installed it. ( This is what the OP has also put.) Now in the Details tab the Date modified is 22 May 2011, the same as in the General tab.
So I believe that the only way to get closest to the manufacturer is to check on the Digital Signature tab (if present). ( One may perhaps never know the
actual date when the manufacturer finalised the file.)
IMO, the only possibility of it - the Date modified as shown in the Details tab and the Digital Signature tab happening to be the same as indicated by you - is when you could have downloaded it on the same day it was signed and put up on the web.
Am I missing anything? I do understand that all this is only trivial and purely academic.

(And to think of it, one may easily manipulate the date created, modified and accessed but not the digitally signed date.)