Different behaviour with wildcards on PubMed using quotation marks or not
Ah PubMed made to much automatism of it. This isn't the exact search string PubMed will proceed. Try it and see the Search Details on the right to find out what PubMed made out of it.

The solution is to put the words in quotation marks. Only in that case PubMed take them as they are without doing something out of your control.

"telerobot*"[tiab] NOT "*robot*"[tiab]