When Close and Push are called concurrently, it may happen that Push attempts to write to an already-closed channel, and trigger a panic.
From a user perspective, it results in logs like this:
http: panic serving 172.19.0.6:50476: send on closed channel
It's probably triggered when download is closed at the same time an upload packet is submitted.
These panics don't crash the server and the inbound is still usable.
mmmray