The 722.6 transmission is known to leak via the O rings in the electrical connector. If the leak is bad enough and doesn't get caught in time, ATF can wick up the cable and damage the electronics in the control box. Sounds to me like the leak wasn't bad enough to need the change yet, but it certainly sounds like the connector plug with the O rings needed to be changed, but that a ten dollar part.

__________________
Len
'59 220S Cabriolet-SOLD and living happily in Malta
'83 240D 351,500 miles original owner-SOLD
'88 560SL 41,000 miles - totaled and parted out
https://sites.google.com/site/mercedesstuff/home
'99 E300 turbo 227,500 miles
'03 SLK320 40,000 miles - gave to my daughter
'14 Smart electric coupe 28,500 miles
'14 Smart electric cabriolet 28,500 miles
'15 Smart electric coupe 28,000 miles