What was done, wasn't wrong necessarily if certain requirements were carried out.
Two of the main things we need to be mindful of within the whole StackExchange community, not just Psychology.SE is the issues of plagiarism, and copyright theft.
Citations and referencing for images and documents helps enormously with this as it credits the original author and shows transparency regarding where the information came from. It seems that when going to the original link provided, although the document is stated to be from somewhere else, the original source was not provided at the target url. Was permission sought to reproduce the document in the manner provided? Was it needed or was the source document produced under a Creative Commons License? This was also not made explicit.
Another point to be made, which is where this question arose is that I highlighted in the comments that linking in the manner provided could be seen as spam. This link was provided in the manner of saying:
Source: PDF, slide 7, from the AAP
and the link went to your own website with no indication of the fact. When linking to the source, it should be to the source and not to an intermediary point or otherwise unless indicated.
Where this would have been fine is if:
- The link to your site is relevant in order to provide more on your answer,
- you declared the link to your own website by saying for example:
I downloaded the source document (<Author>, <Year>) in PDF which was published without any restrictions and hosted it on my own website. I then added reference links to various related resources including the source site, and related material on the topic. This can be found at this address
- the source document is fully referenced at the bottom of the answer.
This way, everything is clear and open, and the reader has a choice to either go to your own website to view the document or go straight to the source.