Yes. Also the prone position on the concrete, with arms drawn behind and handcuffed, in itself made it hard to draw a full breath. The weight of Chauvin and other officers on his back and neck just made it worse.
In that position a person can expel air, but cannot take a breath.
That’s why a person can beg for mercy but still be asphyxiating.
And it answers the macabre statements made on the scenes of a couple of chokehold deaths(Eric Gardner) - “He’s talking, so he must be able to breathe” - as they slowly murder another black man.