It may not necessarily be needing a bleed, a potential clog can cause issues too but sounds like something isn't right. Air in the line can cause issues, feeling like it's spongy, or you need to press harder because you are fighting with that 'springy mass' since it compresses, and fluids really don't. If you seized it and it btfu, unless he replaced every component there could be varnish, or crud got somewhere too. Normally when you burn them that hard, the brake fluid can burn off, boil off, leaving soot, varnish, all sorts of undesirable crud in your system.
I wouldn't go in and directly tell your mechanic, you need to re bleed it, as that may not fix it, but describe what you are feeling, and perhaps ask, do you think it needs to be bled again? otherwise if you say, bleed it, and that's not it, he bleeds as you said, you pay, and still have the problem.
also, since you are there, how does the brake feel, if you want to adjust it's position etc, nows the time as well.
Aaron