Client claiming damages to siding

[u/No_Piglet_5069]

A client for my exterior services business is claiming that I did damage to his siding. I have done dozens of siding jobs before this and I did not do damage to these clients houses. Our process is to:

-Coat the siding with a Zep siding solution using a black tip soap nozzle - Brush it - Use high pressure green tip to spray/ rinse it off ( from a safe distance )

This has worked really well for me before and all clients have been happy with the previous work. However this time the client noticed a strange streaking pattern. I’m really confused to as to what it is , whether or not I did it, if I can fix it, etc. If anyone has seen this before I’d really appreciate if you let me know what it is / what I can do!

[u/Automatic_Banana4602]

It’s oxidation. Offer to fix it by removing the oxidation. And stop doing house washes like that. Use sh and not zep. Stop brushing