Did I do the right thing

I had a roll of Arista Edu Ultra 200 (a.k.a Foma 200) - 120 size - which I was developing in F09 and a roll Eastman Kodak 5222 (Double XX) which I was going to develop in Diafine. I loaded both tanks and ran the Arista first. When I finished fixing the Arista, instead of starting the Ilford method washing process I poured in the Diafine A. Within less than a minute I realized my error, poured out the Diafine A, and started the 5-10-20-40 washing process. Assuming that the Diafine A solution was contaminated with fixer I discarded it and developed the 5222 in fresh Diafine A and B from my replenishment bottles.

The Arista negatives looked good and printed easily. Was the 5-10-20-40 washing process sufficient to remove all of the Diafine A from the emulsion or should I be concerned about long term effects?

I would not be concerned, especially if your fixing time was sufficient.