If the 5k is better than the "normal" month with benefit, it is still better to earn the 5k that month, assuming the benefit is immediately restored on the subsequent months with low income.
> The Social Security office may approve your request for reinstatement. If your request is approved, your temporary benefits start the month following the month in which you made your request. Temporary benefits can last up to six months.
So: it’s not instant. It’s not immediate. And it risks losing the benefits altogether if they mistake a one-time contract for something he could sustain indefinitely.