While Guyana Law indeed stipulate that election results should be declared within 15 days; it does not mean that the announced results are valid and beyond the scope of being contested.
SOPs are the tallied votes for each political party and each group has the results before the election officials make the public announcements.
Major issue here is that the declared results for Region 4 does not match the SOPs.
Hence the current court proceedings because the announced results does not coincide with the SOPs.