Need some advice on an upsetting situation. In short, my dog injured a friend's dog in a scuffle last week. The friend's dog had a small injury to her eye which hasn't responded well to treatment and now she's being referred as an emergency and may have to have her eye removed.
The backstory is that my friend's dog has never taken to my dog. She's 10yrs old, and they are family friends. We also have a 10yr old dog, and they've always got on well. When our younger dog came along (2 now) the friend's dog would snap and snarl if she came near, so we've always had distance between them. We've been walking them together and as long as my dog doesn't get too close (which she doesn't) they are fine. My dog is generally pretty laidback and just keeps her distance. She's never had any problems with other dogs.
On Friday my friend wanted to come back to mine after the walk to look at something. She kept her dog on the lead for the reasons I've mentioned above. She's previously been very apologetic for how her dog behaves (it's not just our younger dog she's grumpy with but other dogs too if she doesn't know them well).
The dogs were both with us as we sat around a table. Then her dog (on a lead) went over to mine (not on a lead) and mine was looking uncomfortable (turning her head away, showing the whites of her eyes) so we called the friend's dog away - she was still on a lead. They separated, and I turned my back to get something and there was a short scuffle. They started fighting and we immediately separated them, it was over in a matter of seconds. My friend who saw the incident said my dog started it, and was biting her dogs face. I think this sounds very out of character, but obviously can't dispute that.
We didn't realise there was anything wrong with my friend's dogs eye until she was leaving about an hour or so later.
I'm obviously worried about my friend's dog, and what happened is awful. But I don't know how to approach the situation. I.e. whether to be apologetic and accept responsibility/blame in some way? I think the rational part of my brain tells me it was one of those things, and that both dogs were at fault. My dog has always been so good at just ignoring my friend's dogs aggression towards her. I appreciate that allowing my friend to come in the house with her dog was a bad decision and I should have refused, and I do feel bad for that. Clearly we had become complacent as they had been walking together so well, and we should have been more cautious. But what about the fact that the injury was inflicted by my dog?
One other thing for completeness - this is somewhat tainted by a previous incident where my (then) toddler picked up a piece of coal from this friend's fireplace and threw in onto their carpet. They were very cross about it, and despite us apologising profusely, and having the carpets professionally cleaned etc, it took a long time for things to return to something resembling normal between us. I'm really worried that if we apologise and accept in any way that this was solely the fault of our dog (as opposed to both of them being at fault in some way) they will run with that and not recognise the part their dog has played in this.
If you could help me see clearly, that would be helpful. Sensitive comments only please, it's all very upsetting.