I thought the same thing. LE said he had a "solid alibi." Since they do not know what time Haleigh went missing, how could he have a "solid alibi." IMO, it is because no one was home. He could show that by showing the number call list on his cell phone. Usually if no one answers the door, the service guy calls you directly rather than go through dispatch. .
Then the question begs why would Misty say she was home and give the AC guys name as an alibi. IMO, the 911 call was staged to make Haleigh disappear after 10 pm. The AC guy may not have been a thought at that time. But during question, Misty was asked about earlier, before Haleigh allegedgly disappeared. Misty may have mentioned the AC guy called then they had to change the story to include him. In setting up Haleigh to disappear after 10 pm, they may not have realized that LE would verify people who were at the MH prior to Haleigh's disappearance.
One thing I am sure of is that GGma Sykes did not see Misty at the MH that night. I just watched the voice stress video which I believe was in the summer time. Misty gave her story about the AC guy and Tommy but did not mention GGma Sykes. Misty never mentioned GGma Sykes being there until TN told the media that GGma Sykes was at the MH about 9 days after Haleigh disappeard. Misty keeps forgetting to include GGma Sykes coming by with the laundry.
I do believe Misty did have contact with both the AC guy and Tommy that day. I don't believe they were at the MH. I think the encounters were changed to the MH. Because those contacts are real memories, Misty is able to remember the story for those contacts.
A solid alibi for the A/C man would require more than a phone call. It's more likely, imo, that he has eyewitnesses who saw him afterward, residents at his next service call, for instance. Nor would a phone call from the A/C guy to Ron prove that the MH was empty when he arrived. There have been several times over the years when service techs and repairmen have come to my house, and I've had to call my husband to answer a question that I couldn't.
I don't see the A/C guy as an afterthought, either. I think they knew very well what questions would be asked. TN was smart enough to present the photo of Haleigh immediately,and I'm pretty sure she was smart enough to know the procedure in a missing person investigation.
From the moment they arrived at the MH, LE would have attempted to establish a "last seen". They would've wanted to know who saw Haleigh that day, who was at the MH, and the times. The A/C guy was mentioned very early on. According to the AMW article I posted below, Merchant said he was cleared within an hour (presumably within an hour of the 911 call). That does seem a little quick to me, but look how fast TN moved that night.

If LE questioned the A/C guy within hours of the 911 call, if not an hour, one has to ask how did LE know the A/C guy was there that afternoon. There are several possibilities:
1. Misty and/or the Croslins told them.
In that case, Misty and the Croslins knew the A/C guy would be questioned and they knew what he would say. From the beginning, any alibi would have to take into consideration the A/C guy's response. If no one was home, Misty would've offered an explanation for her absence.
Now, there's another possibility. Misty was not at the MH and neither she nor the Croslins knew the A/C guy had been there. So, then, how did LE know?
2. A neighbor who saw his truck told them.
3. The A/C man was aware of Haleigh's disappearance very soon and called LE himself.
4. The A/C company owner or manager was alerted very quickly and called LE, or
5. LE noticed an "attempt to service" tag on or near the door.
This would give LE reason to question Misty's claim that she was at the MH when the A/C guy arrived. By August, when Misty took the LVA and hypnosis exams, one would think she would have changed her story. But she didn't.
But the issue here is really whether or not the A/C guy called Ron and Misty answered, establishing that she and Ron were together. In that case, Ron and Misty did know the A/C guy was there. And they knew that the A/C guy's statement would place them away from home and together. To make a claim that Ron left the MH to go to work prior to 5 p.m and Misty was home with the children would have been senseless and downright stupid. When the stakes are as high as they are in this case, why offer an alibi -- and stick to it -- that puts you in one place when you know full well someone will say you were in another?
Having said ALL of that, I think it's quite possible that Haleigh was harmed before 5:00 and Ron's "werk" alibi is sketchy. In fact, I believe that to be at least part of the story. I just have a hard time accepting the notion of this alleged phone call.
All I can say is that this A/C guy had better be good looking because Lord knows, I've spent many nights going to sleep with him on my mind.
As for GGS, until I see evidence to support her story, I'm calling it "a crock".