Can "low fat" eggs have an impact on meringue formation?
I would look at the age of the eggs - take a look at the sell by date on the carton.

If the eggs are fresh it takes more whisking to get it to stiffen up, but once there it will hold longer.

If the eggs are older it doesn't take much whisking to get stiff, but you need to not let it sit out for too long or it will get runny and collapse.

You might also look at the temperature. If the eggs were room temp they would act more like older eggs. If the eggs were cold from the fridge they would act more like newer eggs. 

Sounds like you did a good job of checking for a clean bowl and no yolks. Buying new eggs that are fresh, cold and not served a special low fat diet will probably do the trick.

Hope that is helpful.