In a nutshell: a previous close-to-room-temp superconduction article from this group was retracted from Nature due to two main concerns; (1) a diagram of a measurement needed to confirm superconductivity seemed a lot like one from a 2009 paper, (2) no one else was able to create this material. Oh and that measurement in the 2009 paper was done by the same scientist as the measurement in the retracted paper - and is the source of why the 2009 paper is also under suspicion.
Moreover, it turns out the principal investigator's doctoral thesis has copied substantially from another thesis without proper attribution.
So it seems many are taking a "let's wait and see" approach.
If I was to make such a discovery I'd be hell-bent to have other labs reproduce it independently as fast as possible, as that would, with very high likelihood, earn me a Nobel prize. Not releasing any information about my wonder material because I might want to get a patent on it (which they probably already filed before publishing results anyway) seems just weird.
This would make me feel very confident.
We worked with a high temperature (i.e. liquid nitrogen [1]) ambient pressure superconductor. The experiment was quite unimpressive. You put the small block inside liquid nitrogen, with enough wires [2] and a thermocouple to measure the temperature, and connect it to an oscilloscope. You watch how the temperature decrees in the thermocouple and hope the drawing in the oscilloscope does something weird. There is a lot of room to connect the wires to another device [3], or just show fake data in the oscilloscope. [4]
[1] "high temperature" means more than −195.8 °C = −320 °F = 77 K, that is quite cold for most people
[2] https://en.wikipedia.org/wiki/Four-terminal_sensing
[3] For example, in the OP, they can have a fake ambient temperature superconductor, and connect that cables to a real liquid nitrogen temperature superconductor that is in another room and is put inside and outside the nitrogen by a hidden person.
[4] We had some problems with our superconductor, and we wanted to repeat some measurements. It was sensitive to humidity, and it worked quite well until another student wanted have another stable temperature to compare, and put it in water with ice :( .
See also: Professional illusionists.