Yes but as far as i know, radar sidelobes arent simulated in DCS, apart from decreasing your radar's range if youre near ground level (its mentioned in su-27 manual at least, i havent tested it).
The bugged RWR lock warnings are random and usually happen to multiple players simultaneously (eg. multiple players spread over the map get lock warning from the same plane at the same time). This is a bug in DCS netcode and has been accepted by ED as a bug. The game simply sends out the lock warning message to wrong clients.
Though it would be nice if RWRs in DCS had more realistic limitations.