When he's late, he starts to shrink and won't stop shrinking until he finally gets there. He shrank too small to drive his car so he got out and started running and was in too much of a hurry to worry about the clothes he lost on the way. He knows that he will face consequences for showing up small and he will have to face those consequences before he is grown back to normal size but he still has to get there before he's too small because each millimeter he loses makes him travel that much slower. He's hopeful though because he's pretty sure he can make that final block and only lose one more centimeter.