is this unethical??

[pokerb]

was at the borg this afternoon playin 2/5NL. a man to my left has been very friendly to me when this hand came up. i have about 500-600 in front of me and the BB has me covered. i was in the SB with 2/4 of spades. 2 limpers and the BB chks and we get a flop of K/9/6 of spades. i lead out for 25 the BB calls and the limpers fold. turn comes a A of hearts. i bet out 60 and he raises me 100 more. i think for a while and know he has the A of spades. i announced "raise", before i can say anything thing else he screams out "ALLIN". at this point i had to put out at least 100 for the raise i was going to make, so i put it in.
so i now have about 300 left and ask him if i should call him. i show him my small flush and he says "thats no good, i got u beat, ill show you". so i said "ok, i believe you" and mucked. he then immediatley threw his hand in the muck! i was like wtf, i never seen any1 do this to anyone b4 and he simply said "i lied". what an [censored]! i know for sure i folded the best hand because i believed this [censored]. i learned a new lesson today. is this unethical?