In both the video and Google Translate's pronunciation, I think I understand what you're hearing. It seems to be an implicit glide between the /ɑ̃/ and the /ɛ/ simply as a function of the first being further back: /ɑ/ is open back, whereas /ɛ/ is open-mid front.
If a speaker is not very careful to articulate each sound distinctly (as is normal in spoken language), you can get a "legato" effect. The tongue makes essentially the same motion by moving from back to front as it would make if you were intentionally articulating a /w/.1
However, /w/ is also labial and that feature is absent in both of those unrounded vowels, so it's not a full /w/. At least, that's true of the canonical vowels. One seemingly linguistically informed and France-centred resource claims that many French speakers do actually do some light lip-rounding on the first vowel.
I personally find it hard to tell whether rounding is happening based on your video, but it would better explain your perception of /w/. In any case, if you slow the video down to 0.5x speed, you'll hear more clearly what's happening.
1 The phenomenon of two consecutive vowels is called hiatus. If not resolved, it can lead to just this sort of confusion. One way to resolve it is a brief glottal stop, perceived as a pause between the vowels. Also common in French is liaison, at least where it's syntactically possible.
