First time dog-sitting and he ate raisins...

Just posting on here to check I did the right thing or if I overreacted.

Dog-sitting a young Beagle called Max, I turned my back on him for one second and my bowl of cereal is flying off the table and he is tucking into my muesli with raisins in it. He ingested maybe 5/6 raisins. I knew where the vet was, it was only a minute walk away - thank god - so I rang them up and he is covered and took him there within 5 minutes.

I of course had to ring the owner and shakily tell her what has happened, the most embarrassing thing ever, and she was hit with a bill of £570, which she can claim on. When I heard the number I nearly had a heart attack. He has to have injections and induced vomiting and a blood test.

Now I am home and waiting to hear back from the vet so I can pick him up, the owner seemed fine over the phone but I'm not sure if she was just saying that. Google says he could have been fine or he might not have been, I'm not sure I did the right thing and I will probably get a terrible review and never be able to dog-sit again...

Did I do the right thing or did I overreact?