Afaik, all immeadiately dangerous bacteria get killed by cooking. To completely kill the botulism bacteria for example, you'd have to heat it to 120°C, but the botulism bacteria isn't dangerous, it just produces toxins (that are destroyed at 80°C). The only real concern here are toxin producing bacteria and fungi (that won't sufficiently reproduce in such a short timespan as is necessary for thawing 1kg of meat). It might be bad if you left it out for longer.