I think this was more revenge than a petty response.
Going back a lot of years the office manager used to treat the juniors like scum. They were used as his personal skivvies running errands, going shopping, sent to get his sandwiches, crisps and newspapers etc. his big smirk was to send the youngest to the chemist for his condoms causing tremendous red faced embarrassment in the shop. For Tattlers not old enough to remember, in those days condoms came in packs of three, either lubricated in little sealed sachets or, cheaper in an open packet he, of course, had cheapest. We did wonder if his wife’s unexpected pregnancy was because, not done out of malice but purely for amusement, a compass point was put through the tips.
So what we learn from this is don’t mess with the juniors - certainly not with your rubbers.