i doubt it was temeprature
HIGHLY doubt
those fish should be able to handle a temperature of that level for a short period of time
if in fact your tig died from lack of O2 then your other fish should have died as well such as the ATFs. but this isnt the case.
tigs dont need THAT much oxygen in there water, they have the same o2 requirements as most other south american river fish that we keep.
Tigs come from fast moving, highly oxygenated water, you are completely wrong

My fault.