Does not look like they were scanning below 50 so baseline is probably not from an air leak i.e. CO2. Probably a worn out column bleeding liquid phase. This makes the analysis even more suspect, because columns develop active silica sites which can not only adsorb components but can cause a myriad of decomposition reactions.
My impression is that many people not trained in GC/MS actual use suffer from the misunderstanding that it is somehow the end all of analytical techniques. It's not, it is just one of many tools.
A little trick we use to perform to troubleshoot GC problems is instructive in illustrating just how variable GC/MS analysis can be. Now you may think, if you inject a pure sample of, say PCP into a GC/MS it will certainly identify it as PCP, right?
Maybe, but often not!
When we were having trouble with decomposition of standards due to active sites in the GC system, we would inject a pure standard of PCP. (Yes, that PCP).
It's a useful diagnostic standard, and most productipn GC/MS labs keep it around (you can buy drugs of abuse as MS standards with no DEA license because they come in solutions of sample of such small quantity).
PCP is very prone to degrading in a GC column. Active sites can occur anywhere, but especially in the inject port (front end) and the transfer line to the mass spec ion source (back end).
In a properly functioning GC/MS, you would get a single peak, the spectra would be identified as PCP, the expected result. However if there were active sites in the injection port, the PCP would decompose into two compounds, which would then be separated by a number of minutes retention time, so the chromatogarm would show two distinct peaks (I can't remember the exact masses), neither of which was PCP. If the active sites were in the transfer line, the PCP would again decompose into two compounds but at the end of the column so you would only get one peak, but it was actually the two compounds co-eluting, and the mass spectra would again be characteristic not of PCP but the two decomposition products overlapped.
The moral of the story is that even when you know what you are dealing with a GC/MS is far from infallible, and as I have already mentioned it's not even applicable to many organic compounds.
You could try 4 more suitable extraction methods to get more information from the instrumental analysis - Soxhlet extraction of 3 different samples of the plant material with 1) Methanol 2) Hexane 3) Methylene Chloride and then analyzing each extract. The fourth extraction I would recommend is steam distillation.
You would almost certainly find out a lot more about the profile of compounds in the material by these extraction methods, but at the end of the day, it's an instrumental analysis, and one which may not even reveal the "active factors" at all, it's not magic and it cannot possibly provide you with enough information to be able to say "The active factor is X".