In the Public Service, at least, the departing 50 year old would not get €120K if taking cost neutral early retirement. Even if he/she had more than €60k in the AVC fund to "compensate" for the actuarially reduced PS lump sum, it still would not work. The 150% of final salary tax free is reduced as well if taking cost neutral early retirement. I don't recall off hand what the reduced percentage (per year) is. I assume that if the retiring 50 year old opted for a preserved pension they would get the €120k at 60 - although charges may somewhat deplete the AVC fund in the meantime.
A pre 2004 PS can (not must) retire from 60 without actuarial reduction. Your example could only apply in the PS to a pre 2004 entrant. For post - 2004, cost neutral retirement is only available from 55 with NRA at 65. There are exceptions (eg Gardai).
I assume similar would apply to a DB scheme in the private sector - if the scheme allowed cost neutral early retirement.