I interpret that phrase as "you can do nothing except blaming yourself", not as a joke. Thoughts chain is pretty short:
1. You didn't use an escrow
2. You lost the bitcoins
3. The bitcoins can't be returned
4. You have no an option except blaming yourself (because Bitcoin devs will never make a fork)

People with high IQ tend to verbalize only the final stage assuming that the previous steps are obvious. Jokes work in a similar manner, they require a listener to construct intermediary steps in the mind, one of the steps triggers the reaction in brain. BTW, this is why quite often we see people who don't get a joke, low IQ doesn't allow to construct thoughts chain that make other people laugh.

So, I think "the real dev" wasn't making fun of you.