MuTect2: complex variant expression

Hi, I use GATK3.7 MuTect2 to call somatic variant:
here is the command:

java -jar GenomeAnalysisTK.jar -T MuTect2 -R hg19.fasta  -I:tumor tumor.bam -I:normal normal.bam --dbsnp dbsnp_138.hg19.vcf --cosmic commic_v79.vcf -o result.vcf

and I get a decompressed complex variant like:

chr17   37880996        .       T       TTTA
chr17   37880997        .       G       T

the mapping result looks like:

37880961  37880971  37880981  37880991     37881001  37881011  37881021         
GCGTACCCTTGTCCCCAGGAAGCATACGTGATGGCTG***GTGTGGGCTCCCCATATGTCTCCCGCCTTCTGGGCATCTG
.....................................   ........................................
.....................................***........................................
.....................................***........................................
.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,***,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,***,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
,,..................................TTAT........................................
,,...................................***........................................
.....................................***........................................
... .................................***........................................
... ................................TTAT........................................
,,, .................................***........................................
,,, .................................***........................................
,,,..................................***........................................
,,,..................................***........................................
,,,,................................TTAT........................................
.... ................................***........................................
.... ................................***........................................
,,,, ...............................TTAT........................................
.....................................***........................................
...... ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,***,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
....... .............................***........................................
........ ...........................TTAT........................................

It should be considered compress the two variant to a complex one:

chr17   37880996        .       G       TTAT

Can MuTect2 do anything about this situation?