Okay, here you go. Installed tcpdump on my router, grabbed all traffic to my ipod during the test. The test consisted of opening one webpage (cnet, again), and putting my finger down on the screen twice while the page was loading. I opened the dump in Wireshark and filtered it to HTTP traffic.

http://cl.ly/image/1R0v1P3y0J1u

You can clearly see that traffic stops at 8 seconds, when I put my finger on the device. It then resumes 23 seconds later, when I remove my finger. It then stops again 2 seconds later, when I put my finger back on the device. This was one pageload, no shennanigans, just putting my finger down on the device and scrolling it slightly while the page was loading. It took ~40 seconds to load that page because I had my finger on the screen.

It looks an awful lot like the device is not downloading anything while my finger is on the screen. It certainly didn't just snap to "fully rendered" when I removed my finger at 31 seconds.