WowAce

Solved by the following code change

function Collector:GasBuffDetector(b)
    local timestamp, eventType, hideCaster, srcGUID, srcName, srcFlags, srcRaidFlags, dstGUID, dstName, dstFlags, dstRaidFlags, spellId,spellName = CombatLogGetCurrentEventInfo()
    if foundTarget or (spellName and spellName ~= gasSpell) then return end

    if eventType == "SPELL_AURA_REMOVED" and  spellName == gasSpell then
        ga = gasSpell
    elseif eventType == "SPELL_CAST_SUCCESS" and  spellName == gasSpell then
        ga = gasSpell
    elseif eventType == "UNIT_DISSIPATES" and  ga == gasSpell then
        foundTarget = true
        self:addItem(ga,dstName)
        ga = "No"
    end
    -- Try to detect the camel figurine
    if eventType == "SPELL_CAST_SUCCESS" and spellName == sandStormSpell and srcName == NL["Mysterious Camel Figurine"] then
        foundTarget = true
        self:addItem(sandStormSpell,NL["Mysterious Camel Figurine"])
    end
end

Is this fix meant to work for importing cloud data from gathermate2_data? Still doesn't show data gas clouds for me after trying this out.

This isn't the fix for "doesn't show data gas clouds". You are describing a problem that, to my knowledge, occurs due to incorrect localization (deDE). Take a look at how the clouds are called in the language of your game and compare how they are called in Gathermate2's localization file.

If you look into the addon folder of the Gathermate2 Data is does not contain a gas cloud file to import locations from. Mine works fine for seeing where I picked them up from on the map but no data as to were they have been found by others. I did find an old image that someone had uploaded with their route from back in the original TBC  and have been working on getting my Tom Tom route setup and it works halfway decent but some clouds seem to be a bit off from where they originally were. Here is the image (ZangarMarsh) if anyone wants to take a look and maybe reverse engineer the locations as well: