If you know anything about audio engineering and how affects sound, it's obvious that the Collins link for the before vowels has been clipped fore and aft. The editing on it is really bad. "The" stressed and "the" before consonants were obviously recorded as single words. However they got the pre-vowel "the", it's clearly not recorded or edited in the same manner as the others, and it's badly done.\
I suggest you also look at the dictionary.com pronounciation, which is as I said. They have "thee" as the non-IPA gloss for both stressed and non-stressed, as well as the same IPA gloss for both and pre-vocalic. The difference between the two is more in the, um, stress rather than in the phonetics.
None of this, by the way, in any way depends or is derived from what Setanta says. He, as it happens, is in line with common usage, multi-dictionary definition, scientific usage (which actually does tie "probably" and "likely" to real statistics, which you and OmSigDavid totally blew--I suggest you read the introductory note in any of the IPCC's assessment reports "Scientific Summary for Policymakers").