Gurfateh Bhaji! I had a question. I am aware that gursikh people can't share "jooth" of anyone, but what if the tables are turned? Basically, I went on a trip around India with my friends, and water was very scarce at one particular point. I was the only one who had a bottle of water and when a friend asked if could drink my water I wasn't sure what to do. I just gave it to him though. Was I wrong to do that? I hope this makes sense.
Vaahiguroo Jee Kaa Khaalsaa, Vaahiguroo Jee Kee Fateh
Your heart is pure and I know that you are looking for an answer based on what Sikhi teaches, but I am not capable of providing such an answer. I can only offer what I have learned in my journey, and hope that I don’t do injustice to the teachings of my Guru. Consuming food or drink that has been partially consumed by someone else is a personal choice. If your companion(s) don’t mind taking it from you, that’s not a problem. Personally, I drink from a bottle without it touching my lips if I know there’s a chance that someone else might be in need of it as well, but that’s for their sake.
To directly respond to your question, I think your action of providing a source of hydration was completely the right thing to do.