> when you put the scope probes on, some of the ringing energy goes into the scope and it tends to improve the situation as long as the probe is there.

The software equivalent is so-called "load-bearing printf"s, where for example `printf("broken_var: %i\n",broken_var);` causes broken_var to not get optimized out and so start working correctly. But in hardware that happens even when you (effectively) inspect broken_var in a attached debugger, because the closest thing you have to a debugger (eg, oscilloscope) effectively just is a load-bearing printf.