Handling an out of memory error in any way other than terminating the entire process is very very hard, because the effects of memory exhaustion are felt by all your threads at the same time usually preceded by massive slowdown due to swapping (which will cause other symptoms if there is any real time constraints put on the process).

I'm not saying there are no cases where recovering from allocation errors would be possible but it's not the general case. It's usually easier to treat any allocation error as a fatal error and insure your programs so they don't run out of memory through other means.