What an irresponsible stud dog owner. If someone is paying for stud services, they need to know exactly what has happened: Was there penetration? Did he ejaculate inside her? Did they tie? How long was any tie? This information is part of what someone is paying for, with a stud fee. They're not paying to leave their bitch unsupervised with a male and have zero information back about what exactly happened. Someone needs to be keeping a close eye on the 'business end' of things, and it's typically the stud owner's responsibility.
>The lucky couple have met a few times through the beginning of her season to get to know each other.
This is not actually a good idea because the bitch won't be ready too early and it will only make her snap at him to defend herself from him, which doesn't exactly set up the right dynamic between the two dogs. Some inexperienced males can then be put off by experiencing this and then reluctant to mate when the time is right for fear of getting snapped at again. For the bitch too, it is stressful to put her in the situation where she needs to repeatedly tell him to bog off. The bitch should only be brought to the stud when you think the time is right, not before that.
>Each covering took a bit of time due to his inexperience.
I doubt that's the case. Many dogs take a bit of time to court and woo each other and get in the right mood, regardless of their experience. It is part of the normal procedure that is mating, and nothing to do with inexperience many a time.
>1 - why would this have happened? (I had been told this can happen when the bitch is not quite ready but I couldn't 100% say)
Well it could be for 40000 different reasons. Perhaps she had a stricture and he couldn't enter her. Perhaps it was too early for her, or too late. Perhaps he was inexperienced and couldn't aim right and didn't have an experienced stud handler helping him aim. Perhaps he needs to stand on something. Perhaps she was moving too much and he couldn't do it. And so on. No one can say.
>2 - could it be classed as a slip Mating? (I personally don't think so as they don't know if he penetrated her)
It's really only a slip mating if he not only penetrated her but ejaculated in her, IMO - and only the tie was missing. Even if he penetrated her and thrusted a bit, it's very unlikely to see pregnancy without ejaculation. I think you would know if he'd ejaculated in her and then come out as there would probably be a lot of fluid and semen coming out onto the ground. So I think it's probably not a slip mating.
>when should they put them back in together? As he was totally uninterested after that.
Research shows it takes a stud about 48hrs to make semen of a good quality again, so if he ejaculated, it may need to be that long. If he didn't ejaculate, then once they have had a bit of time apart to rest and get interested again. But really - how long is as piece of string? You haven't mentioned anything about progesterone testing to determine when the right time is, so you've no idea if you are early in trying to mate this bitch or late. It's fine to attempt things that way (and lots of people do) but you should be prepared to risk getting the timing completely wrong and have no idea about anything. IF you want to know when the right time to mate a dog is, the only way to know for sure (especially without an extremely experienced stud), is to progesterone test via the vet to find out when she has ovulated. Personally, I use cytology (done by myself with help from my mentors) to determine when the dog is in estrus, and then I attempt matings throughout estrus. If I don't get successful matings on the second attempt, knowing that it is estrus from the cytology I would do a progesterone test to check where we are at in terms of ovulation. I find this approach minimises the use of progesterone testing whilst also being fairly accurate with timing.