Yeah I wouldn't worry about it. The darker areas of the internet can be kind of dangerous, you get accidentally linked to all sorts of stuff - pop-ups, viruses, weird blank websites, horrific scarring images, it's a real mess, very easy to accidentally get linked to something that seems dodgy. Guess it's the online equivalent of going to a brothel and catching lots of nasty STDs. I imagine this sort of thing happens all the time accidentally. Unless you have hundreds of images on your hard-drive, it's nothing to worry about.
As for the uni, it's not like they have the time to look through everyone's browsing history. If they see a massive spike in data usage because you've been downloading films non-stop then they might chase you up on it, but they're not going to notice anything.