Thankfully, that wasn't the case this time. But that is very much a double-edged sword. The gratification of feeling entirely justified calling in the big guns was short-lived, once it became apparent that the big guns didn't really know what was going on either. I know I'm not the dumbest person on the phone call when the IT admin is saying "Well, that is strange," as I demonstrate the buggy system behavior; if we're both stumped, at least I'm in good company. But on the other hand, that really doesn't get us any closer to fixing the problem.
The issue remains open-ended, and we may or may not have made incremental progress in tracking down the root cause. This is all very much the bulk of my job description - keep things running, fix them (or get someone else to fix them) when they don't - so I don't consider it time poorly spent. Except maybe the few minutes that were lost when the IT admin put me on hold, came back on the line a bit later, and apparently couldn't hear me even though I could hear him, which led to him hanging up and calling me back, which was both a bit of a cluster and not terribly reassuring in terms of the overall infrastructure stability of our enterprise. But so it goes.