The National Academy of Sciences published an opinion piece from a reputable scientist containing fairly strongly worded (for PNAS, anyway) conjecture regarding a possible laboratory origin of SARS-CoV-2. [0]
(you might recognize Relman's name from his work on identifying the human gut microbiome.)
This is particularly strongly worded for this publication:
""" Some have argued that a deliberate engineering scenario is unlikely because one would not have had the insight a priori to design the current pandemic virus (3). This argument fails to acknowledge the possibility that two or more as yet undisclosed ancestors (i.e., more proximal ancestors than RaTG13 and RmYN02) had already been discovered and were being studied in a laboratory—for example, one with the SARS-CoV-2 backbone and spike protein receptor-binding domain, and the other with the SARS-CoV-2 polybasic furin cleavage site. It would have been a logical next step to wonder about the properties of a recombinant virus and then create it in the laboratory. Alternatively, the complete SARS-CoV-2 sequence could have been recovered from a bat sample and viable virus resurrected from a synthetic genome to study it, before that virus accidentally escaped from the laboratory. """
The realm of what is 'possible' is extremely large. This is exactly a reason why serious people without an agenda tend not to play this conjecture game and stick to evidence-based facts.