No, I just went to search if the topic is mentioned in guidelines (which it is, multiple times). I'd then expect a (good) expert to pick on those breadcrumbs and search on how to do that (if they don't have the skills already). If I were working on a computer, I'd try to find IOCs that point to an infection (or lack of evidence for it).

If there's a memory dump to work on, a more in-depth analysis can be done with Volatility on running processes, but it usually falls back on the expert having good skills on that kind of search (malfind tends to drop a lot of false positives).

But at least the guides gave a baseline/starting point that seems to be better than what was described. It's very difficult to prove a negative, so I'd also be careful with the wording, eg: "evidence of a malware infection was not found with these methods" instead of "there's no malware here".