1) The conclusion of the Gemara is that if hot fish was placed in a meaty plate, the fish does not become meaty and one may eat the fish with dairy products. The Rivan, the son-in-law of Rashi, says that if fish was not merely placed in a meaty plate, but actually cooked in meaty utensils, this is different and one may not eat the fish with milk. This is because it is not "Nosen Ta'am Bar Nasan Ta'am" ("Nat Bar Nat"); it is not two steps removed, but rather it is considered one Ta'am, a single transfer of taste. It once happened that eggs were cooked in a milky pot, and the Rivan ruled that one may not use these eggs in a meaty filling since the eggs are considered to be milky.

2) Rashi himself maintains that it makes no difference whether the hot fish was merely placed in the meaty utensil or actually cooked in the meaty utensil. According to Rashi, the only way that the fish becomes "meaty" is if it was actually cooked with meat, but if the fish was merely cooked in meaty utensils it does not become meaty.

B'Hatzlachah Rabah,

Dovid Bloom