I would not expect a "blow out" type failure. Maybe a small tear or hole. The system is always under positive pressure, contaminants could not get into the pbr against that flow. I suppose that the lost algae in the containment area could be vaccumed, dried and added to the animal feed product. A little dirt never hurt a chicken, I've seen what they eat.
No one on the board anyway. I'm sure our good friends at BEHL have it covered, but for sake of discussion.... I'd think they'd just be able to soak a tube/elbow in a solution for a period of time to remove contaminants.
I think they feel like durability of the tubes is covered bc of the 7-layers, but only time will tell on how often this becomes an issue. That will go a long way in determining how they address it. i.e. is it more cost effective to "soak the parts" before replacement or - if issues persist - buy some 14 layer tubing :-)
I dont think there would be any major contamination issues. Since we already breathe whatever garbage is in the air. Are you thinking of cross contamination with other strains? I cant see any contamination issues.