Large response sizes affected by test timeout

[rviscomi]

For example, the resource URL in the following query appears 270 times in the August 2021 crawl, but has 90 distinct response sizes:

SELECT
  respSize,
  COUNT(0) AS req
FROM
  `httparchive.summary_requests.2021_08_01_*`
WHERE
  url = 'https://s1.padlet.net/libraries/pspdfkit/2020.2.2/pspdfkit-lib/pspdfkit-7df7deb39d8228a9.wasm'
GROUP BY
  respSize
ORDER BY
  req DESC

Here are the top 10 response sizes:

respSize	req
4082209	130
4083182	20
4088706	12
4081842	7
4081955	6
4082499	3
4081733	3
3868418	2
4081544	2
3286962	2

So the resource is ~4 MB, and by spot checks of the HAR it takes 30+ seconds to load. IIUC downloading this resource is highly likely to be exceeding the maximum test duration in WPT. When that happens, it seems like the response size is getting cut off.

Is there a way to determine whether a resource's download was interrupted by the test timeout?

(FWIW this resource does not appear to be served with a Content-Length header, which would have been useful to be sure that it's the same resource in all 270 instances)

cc @RReverser re the Wasm chapter