The other issue here might be time - you had a 15-minute window? That's... wrong.
Agreed, and I'd like to add that 15-minute shoots are not where you start, they're where you end. They are what you offer when you are absolutely confident in your abilities and you know you can get the shots you've promised and the client expects. It's easy to think "they can't expect the world, it's only 15 minutes" - but they do. They expect that you know your skill level well enough that when you say you can do it in 15 minutes, you can do it in 15 minutes. And expecting the photographer to know how much time they need to do the job is entirely reasonable.
I'm doing a studio shoot in February, promo/PR pictures for a band. I've been shooting professionally for 13 years, but it's all been journalism/event/concert stuff. I know how to navigate unruly crowds, get in-the-moment shots, tell visual stories, go with the flow, make my way through a sea of people to get where the action is. I look at what's happening before me and find the best way to get the shots I need without impacting the scene at all. Studio is the complete opposite - I'm going to be lighting and posing the band, and I'm going to be able to impact what's in the frame down to the smallest detail. Those are things I am very inexperienced in. So I'm going to rent a studio for at least five hours, possibly even eight, and make a whole day out of it so that I'm sure that when we go home, we're all satisfied with what we've done.
(The band members are friends of mine, so that opens up some possibilities that I wouldn't have with someone I don't know. But that's how you practice this stuff - you shoot in situations and with people you're comfortable with until you know you could do a job of the same quality in half the time or less with people who won't give you leeway because they know you.)
The TL:DR is - don't do 15 minute shoots if you're not certain you can do the shoot in 15 minutes.
If you're planning on doing it yourself using AI or hiring someone else to do it you need to make sure you have permission. Unless your contract explicitly states that you are allowed to make edits/hire a third party to make edits, you are not allowed to do it and will worst-case scenario be required to pay the photographer for doing unauthorized work on his intellectual property.