The one thing I do think that still shows is that he has no intention of actually planting his left foot. If he's genuinely trying to continue running and it's the knee contact that's knocked him over, he'd be stretching forward with his left foot.The law doesn't say much about contact (other than if there is contact, it's a direct free kick) but what it does say is that it's a direct free kick offence if a player challenges an opponent in what the referee considers to be a careless manner.
I thought it was perfectly reasonable to see the knee-to-knee contact by Maehle on Sterling as careless.
There was a good still of it posted earlier, here's another one from a similar angle (and as you can see, it was one of the angles used by VAR).
View attachment 5046
Although it's true that a still image capture doesn't always give the most accurate portrayal of things, I think that in this case it pretty much does - and it supports the idea of a careless challenge.
I don't have a video of it to post but I did watch the replay from this angle several times and as far as I'm concerned, it also clearly shows that there was a careless challenge by Maehle.
I didn't see anything in the clip that made me think Sterling was guilty of simulation.
I'm not arguing the existence of contact - I'm arguing that isn't why he fell over.