I'm very sorry to hear about your loss. I know this is a very hard time. Though the euthanasia solutions we have available are generally given in the vein, they are also approved for the route of administration you witnessed, usually in cases where there is extreme difficulty in finding a vein due to low blood pressure or some other cause making it too difficult to hit the vein. This is not a route of administration that I would personally use in front of the owner, as it is much slower then when given in the vein and is more likely to produce vocalization. I'm very sorry you had to witness this.