It's fascinating that "long" is the biggest tip-off you have, given that Mandarin Chinese (based on the mention of "a noticeably strong Chinese accent") does have words that have the same IPA pronunciation (if you set aside tone) [0] as an American whose speech follows the cot-caught merger [1].
Meanwhile the thing that stood out to me in the initial recording were the vowel sounds: for instance, "young" sounded almost like it rhymed with "long" before training. (That makes sense, since Mandarin similarly has a word with that sound, as can be found in the common last name Yang [2].)
Incidentally, Mandarin has words that sound like "lung" (e.g. the word for "cold" [3]), but if you replace the "l" sound at the front with a "y" sound, depending on which of two transformations you use, it turns the vowel sound into a long o [4] (near rhyme with "lone"). (There is another transformation that you can use that results in a leading "y" in pinyin, but in that specific case, the vowel turns into a long e, and the "y" is largely silent (e.g. the word for "solid" [5]).)
In the last recording, Victor is clearly rushing through the sentence, and you can tell that where he previously had a clear "s" ending for the word "days", it's now slurred into a "th" sound. Agreed that that's actually a net negative for intelligibility.
The wiktionary links below have clips of pronunciation. I will note that not all native speakers have a Standard Chinese accent [6,7], so there are assuredly some differences in pronunciation to be expected depending on exactly which region said individual hails from.
[0] https://en.wiktionary.org/wiki/%E6%B5%AA
[1] https://en.wiktionary.org/wiki/long
[2] https://en.wiktionary.org/wiki/y%C3%A1ng#Mandarin
[3] https://en.wiktionary.org/wiki/%E5%86%B7
[4] https://en.wiktionary.org/wiki/%E7%94%A8
[5] https://en.wiktionary.org/wiki/%E7%A1%AC
[6] https://en.wikipedia.org/wiki/Standard_Chinese
[7] https://en.wikipedia.org/wiki/Help:IPA/Mandarin