Have you ever seen situations where the audio portions of the streams are not identical?

This is a neat way to prove that the data is identical, but expecting it to be different is more akin to debugging the Meridian Sooloos software than debugging your network.

First, UDP has checksumming, so the UDP packet would actually get thrown out by the IP stack before it makes it up to the receiving application, which would result in a lost packet, not a malformed packet.

Next, given that packet loss happens even in common cases, including corruption, there must be a simple acking or nacking scheme here, or else we would hear choppiness often (802.3 and 802.11 is lossy, IP is lossy, UDP is lossy).

The key to IP networking is that they don't have to be bit perfect. They just have to be decently good. TCP ensures that, and UDP helps against corruption, and the application is required to deal with reliability (usually much more lightweight than TCP's solution).

Even if you do see errors on the wire, the assembled audio stream should be perfect, because of retransmissions and sequencing.

Roon