DNS poison and malware questions

Two months ago I was on Omegle just to try it out and I got a "ban" and immediately re-directed to a xxx site. It said the ban would only last two weeks, and it did. I found out that it was a DNS poison and it has happened to a lot of users. Hopefully it was more of a prank than something malicious. And yes, I quit going there.
Anyway, I obviously cleared cookies and website data, and unplugged my internet to reset it. Nothing downloaded into my system, no other sites were re-directing me. I was a bit paranoid so I called Apple. They looked through my computer and didn't find anything wrong. They had me flush my cache and run Clamxav to be sure, and nothing showed up.

I guess my questions are, if the person who did the poisoning had my IP, could they get into my computer? Also, if the xxx site I was re-directed to was bad, could something come in just by visiting it? Or would I see it download or be asked if I wanted to install something? I just want a little peace of mind about the incident.

Thank you.