That sounds very fiesable,the alarm does in fact use IR.Thinking about any voltage surge (or otherwise) this could be the cause,any residual voltage in any of the systems would have drained by this time,the only thing running is the clock,normally this would not set the alarm off,however there is a fault with the clock,it's running slow,you can hear it ticking,and after 6 clicks it misses 2, & then starts again,I will disconnect it and see what occurs. I'll find it.