“ 423. Attributability to service .— (a) For the purpose of determining whether the cause of a disability or death is or is not attributable to service, it is immaterial whether the cause giving rise to the disability or death occurred in an area declared to be a field service/active service area or under normal peace conditions. It is, however, essential to establish whether the disability or death bore a causal connection with the service conditions. All evidence, both direct and circumstantial, will be taken into account and benefit of reasonable doubt, if any, will be given to the individual. The evidence to be accepted as reasonable doubt, for the purpose of these instructions, should be of a degree of cogency, which though not reaching certainty, nevertheless carry the high degree of probability. In this connection, it will be remembered that proof beyond reasonable doubt does not mean proof beyond a shadow of doubt. If the evidence is so strong against an individual as to leave only a remote possibility in his favour, which can be dismissed with the sentence ‘of course it is possible but not in the least probable’ the case is proved beyond reasonable doubt. If on the other hand, the evidence be so evenly balanced as to render impracticable a determinate conclusion one way or the other, then the case would be one in which the benefit of doubt could be given more liberally to the individual, in cases occurring in field service/active service areas.