I am not an Android developer, so I have no way to verify what this guy is saying. That said, it does sound quite plausible:
It's not GC pauses. It's not because Android runs bytecode and iOS runs native code. It's because on iOS all UI rendering occurs in a dedicated UI thread with real-time priority. On the other hand, Android follows the traditional PC model of rendering occurring on the main thread with normal priority.
This is the same reason why Windows Mobile 6.5, Blackberry OS, and Symbian have terrible touch screen performance. Like Android, they were not designed to prioritise UI rendering. Since the iPhone's release, RIM, Microsoft, and Nokia have abandoned their mobile OS's and started from scratch. Android is the only mobile OS left that existed pre-iPhone.