For the record, Amy is becoming one of my favorite SP's to date, so my response will be quite biased. But here are some points that I'd like to make:
1) I have an Android phone and if I turn it off I am usually bombarded with a bunch of emails and text messages when I turn it back on. The time stamp is always when I turn my phone on, and not when the message was sent. This applies to my text messaging as well as emails. Not sure how it works on iPhones and Blackberries, but this is my experience with Android.
2) I have booked ahead with the big Agencies in Toronto, and they ALWAYS require you to call and confirm the day of the appointment. If you don't call in, they will assume you are not interested and give the slot away to someone else. Not sure how it is in Ottawa, but this is my experience with the reputable Toronto agencies. In all fairness to your point though, they don't give the location until it is 100% confirmed.
3) Amy is a sweet girl, and one of the nicest providers I have met (comparable to Peachy on CERB and Effie on TERB). Please don't ruin it for the rest of us just because your friend had a miscommunication. This is exactly why all the young pretty girls get jaded and leave the industry, and we are left with only the "professional sex workers" who are willing and able to put up with rude clients.
4) You can't possibly place 100% of the blame on Amy, even if everything you said is true (that's a big if). One should always confirm the appointment the day of to make sure. Perhaps she should not have given him the location, but that doesn't place the blame solely on her. Even IF she texted him 2 hours before the meeting, I think that's a fair time frame for both parties to confirm. However, she claims that she texted him at 8:30am, so this is a point we won't be able to verify. I think your friend should accept at least some of the blame, and not place it all on Amy.
5) She was willing to offer your friend a discount for the mishap, so she took responsibility for it even though it wasn't entirely her fault. It appears to me as though she took the high road, and your friend was a jerk and yelled at her. I would have been pissed too, but really what does screaming and yelling accomplish? I probably would have tried to negotiate a nice discount for myself or something, although I know it's not always an option for people with SO's.
6) We are all grown ups here, so maybe cooler heads will prevail? Like I said, she's a super cool girl, so I am sure you can still salvage it and work out some kind of a deal with your friend. She's got a smokin hot spinner body, one of the nicest bums around, and a good head on her shoulders. Totally worth the hassle and wait.
Sorry I know I am sounding completely one sided on this, and I apologize if it reads like I am attacking you. But I have seen her a few times now since she started, and I feel that your posts have been really unfair to her. She is a total sweetheart and a beautiful girl inside and out. It was an honest mistake on both sides, and there really is no need to scream and yell and slander the poor girl on the internet.