So what if I suspect (or know) that the person pulling me out of a burning car is a MS-13 thug? At that moment my need is such that I'm not going to complain no matter who offers a hand.
Or, if my daughter were kidnapped and the local mafia (if there were such a thing hereabouts) found her and brought her back to me, I wouldn't say "No, take her back to the kidnappers because I don't like what you do."
And it's the same if a cop helps.
No one can be a bad guy all the time- at least not in every act they perform. They'd never survive no matter what connections they had.
Accepting help isn't the same as endorsing or condoning the other things a person does. You can hate the fact that your rescuer is a hired hitman while still being grateful to him- individually- for helping you at that moment.
If you feel you can afford to slap away a helping hand in a moment of crisis, you are a better person than I.
Yeah, pretty much the same theme as "If a cop saves a life...", but still a little different.