A/Trans Overfill = Leak (duh)

[willyinnv]

Aarrggh! - had my A/Trans [ ‘95 all hydraulic 722.5 behind a 3.2 liter Inline 6] at an indep. shop - just a filter change and partial fluid topoff. Shop overfilled it, and while driving home a motorist reported smoke coming out from underneath (result of A/T fluid leaking onto exhaust pipe). At home, I ‘extractor’ drained approx. 1.5 qts. out, to return to normal levels.
Back to the shop, they apologized, and checked the pan gasket was AOK. But now, I have a (previously tight, dry) trans. that leaks, spotting the floor. It’ll be back to the shop, but......did the overfill & 10 mile drive cause a seal or something to go??? What should I look for? And thanX for your input & help here!