However EI should sell their LHR slots to BA, even if the takeover falls though (they can still codeshare on BA's LHR-DUB flight for example)
What???
Did you just suggest that EI, a profitable company, should sell some of their most valuable assets to another company, so that the other company can make a profit at EI's expense? EI makes a profit on LHR, if it didn't then sure they could consider selling them, but what kind of mad hatter idea is it to sell something making you money, so that your competition can make money on it instead???