FFS
I take it the investigators had never actually tried to use an oscilloscope, or they'd have a bit more of a clue when suggesting that the measurements might be compromised by connecting to it.
Yes, theoretically they could. In practice, they'd have to guess from the screen contents (captured and transmitted up the ethernet connection, thus either slow signals only or non-real-time), modify the settings (which also show up on the screen, so changing them is visible as well as the effect it has on the real display) without alerting the user, or else modify the image he sees by writing it back to the local screen device, in such a way that he makes incorrect decisions and errors in his design.
This is somewhat more difficult than grabbing an endoscope image and modifying it so that the surgeon removes the wrong organ. Ain't gonna happen, because the artifacts of the manipulation will cause the surgeon to discard the instrument long before he makes any use of the images.
Apart from this completely unrealistic scenario, what is the threat from a pwned oscilloscope on the network ? At best a staging post from which to launch further attacks - but if you already have network access, that's not a lot of gain.
Finally, why pick out Siglent for this ? A very low-end brand using linux or some proprietary RTOS for the display. Better to pick on a high-end Tek or Keysight scope running an unpatched out-of-date copy of Windows.
Biting the hand that feeds IT
