Halakhah for Bekhorot 4:10
הֶחָשׁוּד עַל הַשְּׁבִיעִית, אֵינוֹ חָשׁוּד עַל הַמַּעַשְׂרוֹת. הֶחָשׁוּד עַל הַמַּעַשְׂרוֹת, אֵינוֹ חָשׁוּד עַל הַשְּׁבִיעִית. הֶחָשׁוּד עַל זֶה וְעַל זֶה, חָשׁוּד עַל הַטָּהֳרוֹת. וְיֵשׁ שֶׁהוּא חָשׁוּד עַל הַטָּהֳרוֹת, וְאֵינוֹ חָשׁוּד לֹא עַל זֶה וְלֹא עַל זֶה. זֶה הַכְּלָל, כָּל הֶחָשׁוּד עַל הַדָּבָר, לֹא דָנוֹ וְלֹא מְעִידוֹ:
One who is suspect regarding [observing] <i>Shevi'it</i> is not automatically suspect regarding tithes. One who is suspect regarding tithes is not automatically suspect regarding <i>Shevi'it</i>. One who is suspect on both is suspect on regarding purity. There is one who is suspect regarding purity but is not suspect regarding either of the others. The rule is that anyone who is suspect regarding something may not judge or give testimony about it.