So there was water in the system?
There was ...the rad had failed thats why the rad is being changed
Ok, will filling the system back up with ATF get rid of the gylcol issue?
Well there will be no more glycol but your asking the wrong man mate. Gearbox specialist is looking at it so I'm taking his word on trust.
New rad, ATF flush and anti judder can sometimes cure it apparently (if glycol has not been in for too long). Also replacing corroded bits so I've just got to hope they are comfortable with that.
If was running perfect for 15 miles which suggests to me that the torque converter was not damaged but a secondry problem started because the wrong rad and insufficient ATF were in the system.