Crit Reduction
Crit is reduced by 4.8%, but the hit table had 4.8% hit on it which cannot be removed. Thus, the amount of room in the hit table for crits is 100-G-D-M-4.8, with the 4.8% representing the hits that we cannot get rid of. Thus, we our capped with our tooltip crit rate, C, after being reduced by crit reduction (4.8%), matches this value - that is, when C-4.8 = 100 - D - M - G - 4.8 - that is, when C = 100 - D - M - G.
Crit Conversion
4.8% of crits are converted to hits, after the crit cap is imposed. That is, we our crit capped when 100-D-M-G = C, and our hit table consists of 4.8% hit, C-4.8% crit, and the expected D + M + G of other stuff.
Note that either way, the crit cap occurs when C = 100 - D - M - G; note that our observed crit rate in this case is 100-D-M-G-4.8. This is different from the prior theory, when we believed ourselves capped when 100-D-M-G=C-4.8, by 4.8%.
So, yes, our *actual* crit is 100-D-M-G-4.8 when we're capped. But this is when our *tooltip* crit satisfies C=100-D-M-G. And this is only 4.8% lower than it was before.