Rather than focus on the K-II Meter, since my position on the reliability of the device has been mentioned in excess, I think time is best served on other aspects of the featured investigation. TAPS faced a number of challenges in this episode, and while one could debate how well they handled those challenges, I'm not sure they had many options.
The location was ridiculously huge. TAPS has investigated several locations of unusual size over the course of the series (just about any asylum or hotel comes to mind), but this felt a lot more imposing. Investigating a location that size definitely sounds like fun, but it raises a number of complications.
TAPS mentioned most of them in the episode. First and foremost, there's the issue of coverage. How can five investigators, even working on their own, cover a location that large, even accounting for several nights of work? They did have a few hot spots that they could focus on, particularly with the monitoring cameras, but there was still a lot of ground to cover. I think some team members were on their own more in this episode than in any other instance.
(An aside: Kris notes how TAPS members normally wouldn't go off on their own. Really? Because it always seems like Jason and Grant send Kris on her own. Hence calling her the "bait" all the time. Maybe that comment was intended to remind the critics that a cameraman is always with her?)
Getting back to the monitoring equipment, that raises another issue. I'm sure they could have used a lot more equipment, particularly the static cameras and wireless audio. It's hard to tell how much they did deploy, thanks to the editing, but I can't see how it was enough to deal with all the potential problems. Areas would be left untouched, and there's also the very real problem of "site contamination". I know there's some degree of site security involved with the production, but can a building that size really be secured tightly enough?
The dusty conditions were another factor. Not from an investigational point of view (since the "orb" question is never a problem with TAPS), but from a simple safety concern. I don't want to know what the team was breathing during this investigation, but it couldn't have been good. The particulates and mold had to be out of control. And in terms of perception, the dust in the air can mess with your peripheral vision.
With all of those factors working against them, I'm surprised that the team managed to put together anything remotely organized. At least the editors didn't try to shove everything into half an episode! Visually, the site was a lot of fun to see. It was, as I believe someone on the team said, something right out of a horror video game.
In terms of the "evidence", I'm not sure what to think. As always, I dismiss the activity on the K-II Meter, and I don't need to get into the reasons why. I do recall Grant saying that it should be taken with a grain of salt, so there we are. Under normal circumstances, the audio would have been impressive enough to get my attention on any investigation; I'd be scheduling a return visit immediately. But my enthusiasm is tempered by the site security issue, especially with the voices they actually heard.
That brings me to the thermal footage, which was the highlight of the episode (at least according to the presentation). I've described how the FLIR camera works in the past, so my skepticism is based in the science behind the instrumentation. The FLIR images are based on surface temperatures, so something had to be there for the camera to capture.
TAPS apparently thought of that, because they happily point out that the footage of the hallway taken on the adjacent infrared video camera shows no human activity, despite being taken at the exact same time as the FLIR footage. That is intriguing and normally quite convincing, but there are a few mitigating questions to be answered or addressed before it's conclusive.