Davo iv got a female and male mac, and the male done excatly what u decribed above a few days b4 shedding..... he had shed once b4 for me, and i didnt see him do it, but defentally the 2nd time....
First shed, came off no worries, but the 2nd shed, he had some problems getting it off, it took a few soakings and he got it off...... saying this, maybe its a indication that they might be having troubles beginning to shed.....
not 100% tho, im not very experienced myself

peace