Acidcow.com returns two comma-separated URLs

[Tetracerus]

Checklist

• I'm reporting a broken site support
• I've verified that I'm running youtube-dl version 2020.02.16
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar issues including closed ones

Verbose log

/tmp# youtube-dl-py3 -v https://acidcow.com/video/116642-that_was_really_close.html
[debug] System config: ['--prefer-free-formats']
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['-v', 'https://acidcow.com/video/116642-that_was_really_close.html']
[debug] Encodings: locale ISO-8859-1, fs iso8859-1, out ISO-8859-1, pref ISO-8859-1
[debug] youtube-dl version 2020.02.16
[debug] Python version 3.4.10 (CPython) - Linux-3.1.0-7.el6.x86_64-x86_64-with-centos-6.10-Final
[debug] exe versions: avconv present, avprobe present, ffmpeg git-2017-07-31-b664d1f, ffprobe git-2017-07-31-b664d1f, rtmpdump 2.3
[debug] Proxy map: {}
[generic] 116642-that_was_really_close: Requesting header
WARNING: Falling back on generic information extractor.
[generic] 116642-that_was_really_close: Downloading webpage
[generic] 116642-that_was_really_close: Extracting information
[debug] Default format spec: bestvideo+bestaudio/best
[debug] Invoking downloader on 'https://cdn.acidcow.com/pics/20200211/video/that_was_really_close.mp4,https://cdn.acidcow.com/pics/20200211/video/that_was_really_close.webm'
ERROR: unable to download video data: HTTP Error 404: Not Found
Traceback (most recent call last):
  File "/usr/local/bin/youtube-dl-py3/youtube_dl/YoutubeDL.py", line 1925, in process_info
    success = dl(filename, info_dict)
  File "/usr/local/bin/youtube-dl-py3/youtube_dl/YoutubeDL.py", line 1864, in dl
    return fd.download(name, info)
  File "/usr/local/bin/youtube-dl-py3/youtube_dl/downloader/common.py", line 366, in download
    return self.real_download(filename, info_dict)
  File "/usr/local/bin/youtube-dl-py3/youtube_dl/downloader/http.py", line 341, in real_download
    establish_connection()
  File "/usr/local/bin/youtube-dl-py3/youtube_dl/downloader/http.py", line 109, in establish_connection
    ctx.data = self.ydl.urlopen(request)
  File "/usr/local/bin/youtube-dl-py3/youtube_dl/YoutubeDL.py", line 2237, in urlopen
    return self._opener.open(req, timeout=self._socket_timeout)
  File "/usr/lib64/python3.4/urllib/request.py", line 470, in open
    response = meth(req, response)
  File "/usr/lib64/python3.4/urllib/request.py", line 580, in http_response
    'http', request, response, code, msg, hdrs)
  File "/usr/lib64/python3.4/urllib/request.py", line 508, in error
    return self._call_chain(*args)
  File "/usr/lib64/python3.4/urllib/request.py", line 442, in _call_chain
    result = func(*args)
  File "/usr/lib64/python3.4/urllib/request.py", line 588, in http_error_default
    raise HTTPError(req.full_url, code, msg, hdrs, fp)
urllib.error.HTTPError: HTTP Error 404: Not Found

/tmp# 

Description

Videos from Acidcow.com. youtube-dl finds TWO comma-separated video URLs (mp4 and webm) and appears to try to use BOTH as a single URL. Gets a 404 error. Both URLs individually download fine via wget. Same issue using both python 2.6 and 3.4. CentOS-6.

Thanks