AvCanada shows a picture of the panel.
As well as the pilot's AH, there is a copilot's AH plus two turn coordinators. One would like to think that among
fourinstruments you could use to keep the wings level, you would be able to figure out the one that went wrong and follow the other three.
Of course it could also be a vacuum failure and possibly both DGs and AHs were dependent on a single vacuum source, but I would like to think something like a Malibu Juetprop would have redundant vacuum sources.