they could have at least soldered a few pieces of 30AWG wire-wrap wire to the relevant points on the board, put it back together, and measured voltages to see what was going on. They went way overboard burning up the tantalum cap, which apparently burned it open, necessitating the additional jumpers. Then they soldered the burned up cap in backwards, which was pretty blatant. They should have used 12V or so, not 30 or 50, and resoldered it the proper direction to maintain some plausible deniability. Then they wouldn't need the jumpers.
I wonder if the repair technician saw the obvious damage and maybe used a laser trimming tool or something to cut the affected PCB traces and bypassed them with discreet wires. If they had added wires to bring out the test points, they could have measured all the points and figured out how the thing was operating.