The vine-monster shows off the ability to mimic human speech in episode 19, but the only things it says are some variant of 'Help Me'. Now, imagine where it heard that particular phrase, hmmm?
And for that matter, we didn't see any of the other scientists...
The others are said to have evacuated to the airfield. But consider that having seen the plants being used by Kogorr in DC, it's safe to assume that the vine plant might have been taken over by the Skrugg. Now the words "Help me!" gain a whole new meaning, don't they?