It is a special episode in many ways. First of all of course because it is Columbo back after decade.
Some things that I always think about while watching:

- first of all, what was the deal of the experiment? Ok, we see before it, that Max and Elliot meet and respect each other. So there is a clue that they made some kind of agreement and Elliot knew exactly what to expect. But that bothers me in many ways. How did they plan it? if it was so important for the government, probably much more care should be put on observing those guys. Both of them. How did they have a chance to scheme it? it is not so easy to plan, get familiar with maps and exact places and check what is visible in each direction. They needed to plan in detail. It seems that they see each other and next day is the experiment. So I really don't know how it happened. Plus their evening meeting on pier - how was it possible that nobody was checking if they are for sure separated from each other? On the pier they act like they don't plan anything together at all. Rather opposite. So then how it happened? Or maybe Eliot was taught that particular trick during they prison time? but then again - how could he know which points on map would be chosen? In the very end Elliot explains that they planned it 2 days before. But still - how? I can't buy it. Or am I wrong and there is some other explanation?
- why Dyson agreed on that on the first place? He knew his career would be over after such a setback. Ok, I understand that he felt guilty for what happened years ago, but still to risk his all career to make Blake satisfied? I also don't buy it
- was Elliot stupid? ok, he made a trick to cheat the guys from government, but he should be aware that sooner or later (and presumably SOONER than later) everybody will find out that he is tricking everyone. So his career will be very soon over too. Why risking?
- I don't like the experiment at all. So many things can go wrong there, that you can't even count them. The first that pops in my head is that the drivers shoould have been surprised when they see the point on the map. They could have make small cross and there is point now, or they should have remembered that "hmm, I marked my point on total corner of the page, and now I see it in the center". Point on map is not that precise. How Eliot could know where exactly they will park a car to make a picture? the target easily could be covered by something else for example. Also before puting on the eye shield they could just riffle the map by curiosity (by the way, for a while we see one of this guys preparing himself to make a point on "random" page, and you can clearly see that there is no any point prepared! so that ruins the whole later explanation of this trick). So many uncertain things that I can not believe! It makes the episode much worse than it could have been
- the beginning of episode is too long for me. I even think that this is the longest time ever without Columbo on screen (I am not sure if that's true, maybe it is just my feeling of boredom). He appears after 24 minutes. Then it makes it a little boring (plus this dreadful experiment, which takes so long time), so I am always relieved when Columbo finally appears :)
- the collar itself is also interesting. First time Eliot sees it, he sees "danger" and "safe" marks. But how can he know what does it mean? WHERE whould be place the "safe" part to by in fact safe?
- music playing while we first see Columbo, in my opinion doesn't match. It sounds like from a circus or some fairground
- just a funny observation of myself. I like "Friends" sitcom also, and I find it funny that both of Joey Tribbiani's parents are in Columbo. Father is in this episode as a bartender who called the police, and mother is a wicked sister from Murder in Malibu (there are also some other connections between those two series - Alex Brady was Phoebe's boyfriend, Molly Hagan from the same episode and Butterfly in the Shades of Grey was cooking teacher in "Friends)
- Columbo didn't have problems with watching a crime scene? When he can't even stand the sight of blood?
- I am not a big fan of this new Columbo theatrical behavior. I think it started more or less in season seven, and was increasing later on. His thetrical gestures, face expressions, the way he speaks (much slower than before and putting special accent on certain words). We can clearly observe it for example in the scene they look at the crime scene together. And when Columbo visits institute for first time, how impressed he is. On "golden era" it was quite clear for viewer when he is only pretending with this behaviour to misslead the opponent, now it is not so clear (at least for me). Why does he look so intrigued while Elliot is "sensing feelings and emotions" on the crime scene (funny scene by the way, I like how much a fool of himself Elliot makes here)? We know very well that he believes on nothing at all from what Elliot is saying. The old Columbo would do a different expressions - like when he told to Santini "I knew you could do it" after handcuffs trick. The way he's looking here is a total change
- this "mind reading" trick which Elliot uses on Columbo at the begining. It is almost offensively stupid. And because it is SO stupid, I am wondering how much Columbo was bluffing and how much he really believed that. With all the symbol drawing activity. It reminds me a little about number guessing game of Great Santini, it was so easy to break by Columbo, and he even paid some money to get the trick. But here the limit of stupidity is crossed much more beyond. Columbo's reaction on that is similar to his reaction on Murder with Too Many Notes (when given music from movies - "fish, big fish" "shower, knife" etc. Terrible)
- Columbo too easily accepts to lay down on guilottine while the guy is showing him how it works. He knew the day before there was an accident. He doesn't know yet what exactly happened. Ergo, the guilottine could not work properly if it killed its own inventor Max. So I would say he should have been more suspisious about it
- I like the scene when Elliot is shocked to see Columbo inside the plane :D

Despite all the points I wrote above, I still enjoy watching this episode. Of course it is far away from the best in the series, but it still is the pleasure for me