That still makes no sense. The original SARS virus from 2002 is too distant genetically from SARS-CoV-2 to derive the latter from the former in any known way; even RaTG13 is far enough that it's not clear whether e.g. accelerated evolution during serial passaging could result in SARS-CoV-2. The coincidence that makes many people suspect a research accident is that:
1. The Wuhan Institute of Virology had a major program to collect novel sarbecoviruses (viruses different from but related to SARS-1) from nature. No other lab in the world was known to have a comparable program. They'd also proposed to create artificial recombinants of those viruses with a furin cleavage site. Such a site is uncommon among related natural viruses, but present in SARS-CoV-2.
2. SARS-CoV-2 was first detected in Wuhan.
The first point does not apply to Vector, or to any other lab outside Wuhan.
Information about blast at «Vector» BSL4 lab is state secret now, I cannot find information about internal situation at «Vector».
My guess: perhaps the virus was being kept alive in living organisms (deliberately or accidentally).
Then the sequence of events looks as follows:
* September 16, 2019 - Explosion of a gas cylinder at the territory of the "Vector" laboratory in Kol'tsevo, Novosibirsk.
* Military personnel arrive to conduct fire inspection (breaking doors in each laboratory room searching for fire traces), without proper biological protection.
* During the fire inspection, the military take away some property from the laboratory (captured on video) and likely get infected with the virus from animal carriers.
* October 11, 2019 - Joint training of Chinese and Russian special police in Kol'tsevo, Novosibirsk, 40 Chinese policemen arrived.
* October 16, 2019 - First report of a sudden increase in cases of atypical pneumonia in Krasnoyarsk Krai, in Siberia - 700 cases per week. («Arguments and Facts on the Yenisei» No. 42, 2019)
* October 18, 2019 - Military World Games begin in Wuhan, attended by servicemen from Russia, from which the virus likely started spreading worldwide.
* November 2019 - Schools are quarantined due to an outbreak of atypical pneumonia in Krasnoyarsk, Rostov-on-Don, Orenburg, and Samara regions.
* November 2019 - Russian armed forces begin «training» to blockade infected regions of Russia.
1. The Wuhan Institute of Virology had a major program to collect novel sarbecoviruses (viruses different from but related to SARS-1) from nature. No other lab in the world was known to have a comparable program. They'd also proposed to create artificial recombinants of those viruses with a furin cleavage site. Such a site is uncommon among related natural viruses, but present in SARS-CoV-2.
2. SARS-CoV-2 was first detected in Wuhan.
The first point does not apply to Vector, or to any other lab outside Wuhan.