Pull query gives partial results with status code 200 - Server logs json parsing error

[GMaystorski]

Describe the bug
Using a distributed KSQL setup with HA Routing enabled, when running pull queries, every once in a while a query would return partial results, with the server logging a json parsing exception (attached screenshot). We assume this error is due to some unknown connection issue during HA routing communication. However more importantly, the server should not return a status code of 200 on partial results, as we can not handle this at all.

To Reproduce
Steps to reproduce the behavior, include:

1. v0.29.0
2. Cannot provide data - all that is important is a fixed amount of keys spread across multiple instances (3 to 5).
3. SELECT * from TABLE (we know exactly how much data is in it and it is not changing during the test run)
4. Spam the above query (e.g 3 threads spamming every 100-200 millis).
5. Soon you should receive a partial result (if you have 500 keys, the server returns 380 for example)
6. The error from the screenshot should be seen in the logs of the instance you queried

Expected behavior
We expect when there is an error in the server during a pull query, to receive a non-200 status code, preferrably a 5xx

Actual behaviour
A clear and concise description of what actually happens, including:

1. Partial results with 200 status code - using java client and plain http client yields the same result
2. No errors on client side - just partial data
3. KSQL logs in screenshot