Another time I watched as a tech student with doubles had a very significant freeflow (apparently losing half his air on descent) and the instructor continued the deep air dive at 175 ft (for most or all of the planned dive time). This one also turned out OK, but this same tech instructor exhibited poor judgement on several other (recreational training) occasions I personally witnessed and he later went on to perish a few years later in a dive accident along with his student and "an observer" in 275-300 ft of water using trimix.
Another time, I was diving on a 190 ft deep wreck, solo at the same time a tech training class was ongoing from the boat, and when I finished my deco and safey stop and got on the boat, I found the student near death being administered oxygen from my O2 bottle (since the tech instructor had brought none). According to his computer, this student diver never made it below 20 feet and his dive time was less than one minute, however his instructor descended ahead of the student on the descent line and made it to 135 ft before he "felt lonely" and came up a few minutes later. The student had heart problems and almost died from drowning.
I've seen lots of "bad/stupid stuff" happen during strictly recreational dive training, but after last weekend I'm really beginning to get a "bad taste in my mouth" about how some tech training is still being done.