Yeah it was risky. It is quite common for excessive security practices to actually decrease security and that particular example was not nearly the most egregious one in that company.
I don't really get why you did it though. You risked your job, and potentially regulatory issues for the company just to get a build done? I'd have just submitted a request to unblock the official download site. Then it's security's problem.
I've also come across this at a major international company. Came there to install an update. Too big to email so I had a clean USB stick. No way to use it in their workstations though, so the IT guy offered to just walk to the DC and plug it directly into the server.
Pretty sure that was not the intention of that policy. The problem is, that they didn't seem to have considered this usecase at all. More security theater than anything.