No query fields MATCH weight info for a doc in debug?

[Derek Poh]

Hi

I came across a document that does not has the query field MATCH weight 
information in the debugbut the query fields do have the search term in 
them.
What can cause this?
Here is some info of the document.

Search keyword is "LED"

The search fields and their values,
P_CatConcatKeyword = E14 LED bulbs
P_NewShortDescription = TIWIN TUV GS CE RoHS Certified LED Bulb, 3W 5W 
7W 9W 11W 13W
P_VeryShortDescription = LED Bulb
spp_keyword_exact =  LED,led bulb,led bulb light,solar garden lights

This is the partial debug info for the document,
2.9332387 = (MATCH) sum of:
  2.516484E-7 = (MATCH) max of:
    2.516484E-7 = (MATCH) weight(spp_keyword_exact:led^1.0E-5 in 
1775174) [DefaultSimilarity], result of:
      2.516484E-7 = score(doc=1775174,freq=1.0), product of:
        3.8561673E-8 = queryWeight, product of:
          1.0E-5 = boost
          13.051737 = idf(docFreq=38, maxDocs=6684479)
          2.9545242E-4 = queryNorm
        6.5258684 = fieldWeight in 1775174, product of:
          1.0 = tf(freq=1.0), with freq of:
            1.0 = termFreq=1.0
          13.051737 = idf(docFreq=38, maxDocs=6684479)
          0.5 = fieldNorm(doc=1775174)
  2.8821251 = (MATCH) weight(P_ProductId:1119054943^38.0 in 1775174) 
[DefaultSimilarity], result of:
    2.8821251 = score(doc=1775174,freq=1.0), product of:
      0.17988378 = queryWeight, product of:
        38.0 = boost
        16.022152 = idf(docFreq=1, maxDocs=6684479)
        2.9545242E-4 = queryNorm
      16.022152 = fieldWeight in 1775174, product of:
        1.0 = tf(freq=1.0), with freq of:
          1.0 = termFreq=1.0
        16.022152 = idf(docFreq=1, maxDocs=6684479)
        1.0 = fieldNorm(doc=1775174)

Thanks,
Derek