Yeast starter cross contamination?

[sancycling]

So I made a couple of yeast starters as usual. Boiled DME for 10 mins in earlenmayer flask, cooled, pitched yeast, stir plate, covered with loose foil. Pitched fresh WLP545 in one flask and Washed WLP007 that had been in the fridge for about 3.5 months in the other.
The flask with WLP545 took off in about 12hrs as usual. The one with WLP007 took off in about 48 hrs, quite stong and with lots of kraussen.
I have my doubts that the washed yeast was in good condition as it looked a bit dark before pitching in the starter.
I didn't pitch the washed WLP007 as it smelled VERY belgiany, lots of bannana smell, similar to the WLP545 starter.

Is it possible that yeast from one starter contaminated the other one? Just by being side by side? Could it happen that the washed yeast was dead and the fresh wort was too tempting for the yeast in the other starter?

Thanks

 

[giraffe]

Unlikely, if you have reasonable practices. And it would take a good amount of yeast to get a vigourous starter in 48 hours. That isnt one lucky airborne cell that somehow got out from beneath the one foil, floated over, and snuck under the other foil and fell directly in the other wort.

Either the wlp007 was infected before storage, or its the middle of summer and your starter fermented at 80 degrees, which threw weird esters, are much more likely scenarios.