catcher take down

[CecilOne]

I know we've discussed all the possible runner/fielder plays before, but please save me a long search and opine about this.

Runners at 3rd, 2nd; fly ball to center. Both runners tag, throw comes home.
R1 upright beats the throw, but slips on plate and goes feet first past the plate into the catcher who goes down.
R2 about 2/3 of the way to 3rd, but catcher is flat on the ground and can't throw.