TM vanished durring battle

[Emrech]

Hi, while I was puting TM (Shadow Claw) on my Aipom wild pokemon attacked me (I was not paying attention to what I was doing in background - riding through grass). Dialog, that let me choose which attack should I forget, popped up. After few seconds battle engaged (i just ran away), but the move-learning dialog also disapeared and so did the TM from my inventory (and the move was not learnt by pokemon).