Definitely, both should have used a condom if they didn't want a baby, men need to take more responsibility for protection rather than doing nothing and then blaming the women when they end up pregnant.
I can understand forgetting, I do think something was a bit off though. Charlie said he dropped her off at asda to get it whilst she did her food shop, at some point within the next few weeks you'd think either she would have realised she didn't take it and mentioned it to him, or he would have brought it up, even just a simple 'did you get the pill earlier?' when he took her home from the shop. I know my husband would have, and I'm pretty certain I wouldn't have completely forgotten about it for weeks if I genuinely didn't want to have a baby. The whole thing was a bit weird tbh